Features
- Reads process signals from ±200 mV to ±600V or ±2 mA to ±5A full scale
- Accuracy ±0.01% of reading ± 2 counts
- Absolute and ratiometric mode for bridges and potentiometers
- Error less than 0.01% of full scale for absolute ranges, less than 0.01% of reading for ratiometric measurements
Certificates of Compliance
Laureate™ 1/8 DIN Digital Panel Meters for digital process
are a cost-effective solution for process signals such as 4-20 mA, 0-10V, or 0-5V. Full-scale voltage input ranges from ±200 mV to ±600V and current ranges from ±2 mA to ±5 A are jumper selectable. All ranges are precalibrated at the factory, so that recalibration is not needed when changing ranges or signal conditioners. The 200.00 mV and 2.000 V ranges provide a high input impedance of 1 Gohm to minimize the load on the voltage signal.The meter can be set to absolute and ratiometric (or potentiometer follower) mode by making a software selection. In this mode, the meter tracks a ratio of the applied excitation voltage and is unaffected by changes in the excitation voltage. Ratiometric measurements provide an exceptional accuracy of 0.01% of reading ± 2 counts. This capability is used with the meter's 5V or 10V excitation output for load cells and Wheatstone bridges, and with the meter's 5V excitation output for potentiometers which track wiper position.
All signal conditioner board ranges are factory-calibrated, with calibration factors for each range securely stored in an onboard EEPROM. These factors can be scaled via software to accommodate external shunts, enabling field replacement of signal conditioner boards without necessitating recalibration of the associated digital panel meters. For optimal accuracy, factory recalibration is recommended annually. All Laurel Electronics instruments undergo factory calibration using the industry-leading Fluke calibrators, which are recalibrated yearly and certified traceable to national standards, ensuring the highest level of precision and reliability.
The optional extended Laureate computer board enhances Laureate Digital Panel Meters by displaying rates derived from successive readings and enabling highly accurate custom curve linearization. For example, it can calculate liquid volume or flow rate in a horizontal cylindrical tank using levels from a 4-20 mA transmitter. Setup is straightforward: users input up to 180 data points into a spreadsheet or text file, and the computer calculates spline-fit segments, which are then downloaded to the meter for precise operation.
Laureate Digital Panel Meters are easily programmed with Laurel’s free Instrument Setup Software, downloadable from our website and compatible with Windows PCs, requiring a data interface board for setup.
Scaling is from -99,999 to +99,999 (five full digits) with any decimal point to display readings in engineering units, such as PSI. Three scaling methods are user selectable: scale and offset, two-point method, and system-level calibration using actual transducer signals.
High read rate of up to 50 or 60 conversions per second, the Laureate™ Digital Panel Meters use a Concurrent Slope (US Pat. 5,262,780) analog-to-digital conversion to integrate signals over a full power line cycle (50 Hz or 60 Hz). This read rate enables peak and valley capture, real-time computer interfacing, and control applications. Peak and valley values are automatically captured and can be viewed using Laurel’s free Instrument Setup Software (compatible with Windows PCs) or transmitted as serial data.
Digital signal filtering modes can be selected to ensure stable readings in electrically noisy environments.
- An unfiltered selection provides true peak and valley readings and aids in control applications.
- A batch average filter selection averages each 16 conversions.
- An adaptive moving average filter selection provides a choice of 8 time constants from 80 ms to 9.6 seconds. When a significant change in signal level occurs, the filter adapts by briefly switching to the shortest time to follow the change, then reverts back to its selected time constant. An Auto setting selects the time constant selection based on signal noise.
Two tare functions: auto-tare and manual tare. In auto-tare, an input line is grounded by an external pushbutton. In manual tare, the tare value can be entered manually via a control input pushbutton or using Laurel's free Instrument Setup Software.
Peak and valley values are automatically captured. These may be displayed via a front panel pushbutton command or control signal at the rear connector, or be transmitted as serial data.
Two rear panel control Inputs (CMOS/TTL levels, logic 0 = tied to digital ground, logic 1 = open) or dry contacts that can be set to control / activate 14 meter commands.
An (isolated) 5, 10, 12, or 24 Vdc excitation output is standard to power transducers or two-wire transmitters. Ratiometric operation, which automatically compensates for changes in the applied excitation, is jumper selectable for applications, such as bridges, where the signal to be measured is proportional to the excitation level.
Modular Design for Maximum Flexibility at Minimum Cost
All boards are isolated from meter and power grounds. Optional Plug-in-Play boards for communications and control include Ethernet, WiFi, serial communication boards, dual or quad relay boards, and an analog output board. Laureates may be powered from 85-264 Vac or optionally from 12-32 Vac or 10-48 Vdc. The display is available with bright red or green 0.56" (14.2mm) high LED digits. The 1/8 DIN case meets NEMA 4X (IP65) specifications from the front when panel mounted. Any setup functions and front panel keys can be locked out for simplified usage and security. A built-in 5, 10, 12, or 24 Vdc excitation supply can power transducers, eliminating the need for an external power supply. All power and signal connections are via UL / VDE / CSA rated screw clamp plugs.
The Laureate™ Series features modular design with up to 7 isolated plug-in boards, applicable to all Laureate 1/8 DIN Digital Panel Meters.
Modular Hardware
The design of the Laureate™ Series is modular for maximum flexibility at minimum cost. All boards are isolated from meter and power grounds. The base configuration for a panel meter or counter consists of a main module (with computer and plug-in display boards), a power supply board, and a signal conditioner board. Optional plug-in-play boards include an isolated setpoint controller board, an isolated analog output board, and an isolated digital interface board. Modular design and a choice of plug-in options allow the Laureate to be customized for a broad range of applications from simple monitoring to control and computer interface. There can be up to five plug-in boards in a 1/8 DIN Laureate.
Connecting Laureate Digital Panel Meters to a Local Area Network (LAN)
Up to 30 Laureate Digital Panel Meters and/or LT Transmitters can be configured for RS485 and daisy-chained to an LT Transmitter using Laurel’s High Speed Ethernet-to-RS485 converter board for seamless LAN integration. Alternatively, Laurel LTE series Ethernet transmitters can connect directly to a LAN via an Ethernet cable. Setup for both configurations is streamlined using Laurel’s free Instrument Setup Software, which simplifies node discovery and transmitter configuration.
Flexible Communication Options for Digital Panel Meters
Laureate Digital Panel Meters can be equipped with Laurel communication boards to support various interfaces and protocols. These include serial interfaces with ASCII or Modbus RTU protocols, and Ethernet interfaces with web access, ASCII, or Modbus TCP/IP protocols, ensuring versatile connectivity for your commercial applications.
DC Voltage
| DC Voltage Range | Resolution | Input Resistance | Error at 25°C |
|---|---|---|---|
| ±200.00 | 10 µV | 1 GΩ | 0.01% of FS ± 2 cts |
| ±2.0000 | 100 µV | 1 GΩ | 0.01% of FS ± 2 cts |
| ±20.000 | 1 mV | 10 MΩ | 0.01% of FS ± 2 cts |
| ±200.00 | 10 mV | 10 MΩ | 0.01% of FS ± 2 cts |
| ±300.00 | 0.1 V | 10 MΩ | 0.01% of FS ± 2 cts |
| ±600.00* | 0.1 V | 10 MΩ | ± 0.4 V |
| * ±600.00V range not ETL certified. | |||
| Recalibration: All ranges are calibrated at the factory. Recalibration is recommended every 12 months. | |||
DC Current
| DC Current Range | Resolution | Input Resistance | Error at 25°C |
|---|---|---|---|
| ±2.0000 mA | 0.1 µA | 100 Ω | 0.01% FS ± 2 cts |
| ±20.000 mA | 1.0 µA | 10 Ω | 0.01% FS ± 2 cts |
| ±200.00 mA | 10 µA | 1 Ω | 0.01% FS ± 2 cts |
| ±5.000 A | 1 mA | 0.01Ω | ± 10 mA |
DC Voltage & Current
| Display | |
|---|---|
| Readout | 5 LED digits, 7-segment, 14.2 mm (.56"), red or green. |
| Range | -99999 to 99999 or -99990 to 99990 (count by 10) |
| Indicators | Minus sign, 2 red LED lamps |
| A-to-D Conversion | |
| Technique | Concurrent Slope™ (Pat 5,262,780) |
| A-to-D rate | 60/s at 60 Hz, 50/s at 50 Hz |
| Output update rate | 56/s at 60 Hz, 47/s at 50 Hz |
| Display update rate | 3.5/s at 60 Hz, 3/s at 50 Hz |
| Reading Accuracy | |
| Error at 25°C | 0.01% of full scale ± 2 counts (except 5A range) for absolute measurements. 0.01% of reading ± 2 counts for ratiometric measurements. |
| Span tempco | 0.003% of reading/°C |
| Zero tempco | 0.1 count/°C |
| Noise Rejection | |
| CMR, DC to 60 Hz | 130 dB |
| NMR at 50/60 Hz | 90 dB with min filtering |
| Maximum Signal | |
| Max applied voltage | 600 Vac for 20, 200 and 300 V ranges, 125 Vac for other ranges |
| Overcurrent protection |
25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5 A |
| Power | |
| Voltage, standard | 85-264 Vac or 90-300 Vdc |
| Voltage, optional | 12-32 Vac or 10-48 Vdc |
| Frequency | DC or 47-63 Hz |
| Power consumption (typical, base meter) | 1.2W @ 120 Vac, 1.5W @ 240 Vac, 1.3W @ 10 Vdc, 1.4W @ 20 Vdc, 1.55W @ 30 Vdc, 1.8W @ 40 Vdc, 2.15W @ 48 Vdc |
| Power Isolation | 250V rms working, 2.3 kV rms per 1 min test |
| Excitation Output (standard) | |
| 5 Vdc | 5 Vdc ± 5%, 100 mA (jumper selectable) |
| 10 Vdc | 10 Vdc ± 5%, 120 mA (jumper selectable) |
| 12 Vdc | 12 Vdc ± 5%, 100 mA (jumper selectable) |
| 24 Vdc | 24 Vdc ± 5%, 50 mA (jumper selectable) |
| Output Isolation | 50 Vdc from signal ground |
| Ratiometric operation | 5 Vdc or 10 Vdc for bridge circuits, 5 Vdc for potentiometers |
| Analog Output Board (optional) | |
| Output levels | 4-20 mA, 0-20 mA, 0-10V, -10 to +10V (jumper selectable) |
| Current compliance | 2 mA at 10V ( > 5 kΩ load) |
| Voltage compliance | 12V at 20 mA (< 600 Ω load) |
| Scaling | Zero and full scale adjustable from -99999 to +99999 |
| Resolution | 16 bits (0.0015% of full scale) |
| Step function response | 80 ms to 99% of final value (typ) |
| Isolation | 250V rms working, 2.3 kV rms per 1 min test |
| Relay Output Boards (optional) | |
| Relay types | 2 Form C contact relays or 4 Form A contact relays (NO) 2 or 4 Form A, AC/DC solid state relays (NO) |
| Current tatings | 8A at 250 Vac or 24 Vdc for contact relays 120 mA at 140 Vac or 180 Vdc for solid state relays |
| Output common | Isolated commons for dual relays or each pair of quad relays |
| Isolation | 250V rms working, 2.3 kV rms per 1 min tes |
| Communication Boards (optional) | |
| Board Selections | RS232, RS485 with dual RJ11 connectors, RS485 with dual RJ45 connectors, USB, High-Speed Ethernet, USB-to-RS485 gateway, High-Speed Ethernet-to-RS485 gateway, WiFi with built-in antenna plus USB & RS485, WiFi with external antenna plus USB & RS485 |
| Protocols | Laurel Custom ASCII (serial), Modbus RTU (serial), Modbus TCP (Ethernet or WiFi) |
| Digital addresses | 247 (Modbus), 31 (Laurel ASCII), |
| Isolation | 250V rms working, 2.3 kV rms per 1 min test |
| Signal Connections | |
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| Environmental | |
| Operating temperature | -40°C to 70°C (-40°F to 158°F) |
| Storage temperature. | -40°C to 85°C (-40°F to 185°F) |
| Relative humidity | 95% at 40°C, non-condensing |
| Protection | NEMA-4X (IP-65) when panel mounted |
| Mechanical | |
| Enclosure | 1/8 DIN, high impact plastic, UL 94V-0, color: black |
| Mounting | 1/8 DIN panel cutout required: 3.622" x 1.772" (92 mm x 45 mm). |
| Dimensions | 4.68" x 2.45" x 5.64" (119 mm x 62 mm x 143 mm) (W x H x D) |
| Maximum panel thickness | 4.5 mm (0.18") |
| Tightening Torque - Connectors | Screw terminal connectors: 5 lb-in (0.56 Nm) |
| Tightening Torque - Pawls | Digital Panel Meter Case Pawls: 5 lb-in (0.56 Nm) |
| Weight of base meter | 210 g (7.4 oz) typical (DPM, counter, timer, 6-digit remote display) |
| Weight of option boards | 30 g (1.0 oz) typical per board (analog output, relay output, communications) |
| General | |
| Programming Methods | Four front panel buttons or via Laurel's free Instrument Setup Software, which runs on a PC under MS Windows. |
| Security | Lockout options include using the front panel buttons, the free Instrument Setup Software, or a hardware jumper. |
| Warranty | 3 years parts & labor |
| Recalibration: All ranges are calibrated at the factory. Recalibration is recommended every 12 months. | |
Free Instrument Setup Software for Series 2 Laureates
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| 1/8 DIN Digital Panel Meters | DIN Rail Transmitters |
Free Downloadable Windows-based Instrument Setup (IS) software (Data Interface Board Required) for use with our programmable Digital Panel Meters, Scale Meters, Counters, Timers, Remote Displays, and Transmitters, are an easy method to set up Laureate 1/8 DIN digital panel meters, counters, timers, remote displays, and DIN-rail transmitters, as explained in the Instrument Setup Software Manual. Laureate 1/8 DIN instruments can also be set up from the front panel, as explained in their respective Owners Manuals. Instrument Setup software is of benefit whether or not the PC is connected to the instrument.
- When the PC is connected to the instrument, Instrument Setup software can retrieve the setup file from the instrument or open a default setup file or previously saved setup file from disk View Setup, then provides graphical user interface (GUI) screens with pull-down menus applicable to input, display, scaling, filtering, alarms, communications, analog output, and front panel lockouts. Fields that are not applicable to the instrument as configured are either left out or grayed out. Clicking on any item will bring up a detailed Help screen for that item. After editing, the setup file can be downloaded, uploaded to the instrument, or saved to a disk. The same setup file can then be downloaded into multiple instruments.
- When the PC is not connected to the instrument, the above GUI screens can be used to set up a virtual instrument. The setup file can then be saved to disk. Switching toView Menu then brings up a screen with the required front panel programming steps. This view can be printed out for use at the instrument site and to serve as a hard copy record.
Download Free Instrument Setup Software
Installation
Set User Account Control (UAC) of MS Windows to "Never notifiy me" so that Instrument Setup Software can create directories. The UAC change screen can be reached as follows:
- Under Windows 7, click on the Windows Start button in the lower left of the desktop and enter "UAC" in the search field.
- Under Windows 8, navigate to Control Panel, then to the "User Accounts and Family Safety" section, and click on "Change User Account Control Settings."
- Under Windows 10, click on the Windows Start button in the lower left of the desktop, then on "Settings", and enter "UAC" in the search field.
- Reboot your computer for the changed UAC setting to take effect.
RJ11-to-DB9 cable with rear view of DB9 connector to PC
RS232 cable, meter to PC, P/N CBL01
Laureate 1/8 DIN Laureate instruments must be equipped with a serial communications board and be connected to the computer via a serial communications cable. The connection can be via RS232, RS485, USB or Ethernet. Following setup, the serial communications board may be removed from the instrument if desired. The wiring of the RS232 cable is illustrated above with end views of the two connectors.
Laureate LT Series transmitters come standard with a 3-wire serial interface, which can be jumpered for RS232 or RS485.
Laureate LTE Series transmitters come standard with an Ethernet interface.
Meter Setup Screens
Click on any of the reduced screens below for a full-size screen view, then click on the Back button of your browser to return to this page. The screens examples below are for a fully-loaded Series 2 Digital Panel Meter (DPM), which is connected to the PC via RS232. If the meter is a Series 1 meter (pre-2007), this is sensed by the software, and somewhat different screens are brought up. Please see Series 1 setup screens.
Welcome Screen
From the computer desktop, click on Start > Programs > IS2 > IS2. Or click on the IS icon on your desktop. This splash screen will be displayed for three seconds. The software revision number is in the lower right.
Communications Selection Screen
Specify your desired communication protocol and the serial communications bus type, which should match the jumper setup of the instrument. Select None if the PC is not connected to the instrument.
Establish Communications Screen
If you selected RS-232, you will be asked to specify the PC Com Port and Baud Rate, which should match the jumper setup of the instrument. Click on Establish. With the right settings, the Communications Established field will light up in green, and the Meter Type will be recognized. If so, click onMain Menu.
Main Menu Screen
Click on File > Default Setup to retrieve the default setup file from disk for your type of meter. Click on File > Open Setupto retrieve a previously saved setup file from disk or on File > Save Setup to save your edited setup file to disk. Click onDPM > Get Setup to retrieve the setup file from your meter or on DPM > Put Setup to download your edited setup file into the meter.
DPM Input + Display Setup Screen
From the Main Menu, click on View > Setup, then on theInput+Display tab. You can now specify the meter hardware, signal type, display mode, and functions of control inputs A and B. Clicking on any item brings up a pull-down menu with the available choices.
DPM Scaling Setup Screen
Click on the Scaling tab, which provides three scaling methods to relate the signal to the displayed reading: 1) Scale and Offset method, 2) Coordinates of two points method, and 3) Reading Coordinates of Two Points method. The last method uses actual high and low signals, and the computer will prompt you.
DPM Filter Setup Screen
Click on the Filter tab, which allows you to specify the digital filter time constant (if any), the adaptive filter threshold, and whether Peak / Valley values are filtered or unfiltered. As for all setup screens, clicking on the F1 key while an item is highlighted brings up a Help screen for that item, as illustrated.
DPM Relay Alarms Setup Screen
Click on the Relay Alarms tab, which allows you to set up Alarms 1 and 2 for the optional dual relay output board. Clicking on any of the four numeric fields changes these to green and brings up a special field to enter the desired numeric value, which is tied to the displayed reading.
DPM Communications Setup Screen
Click on the Communications tab so set up serial communications. In particular, you can special the Serial Protocol and the meter address if multiple meters are to be addressed on the same serial data line.
DPM Analog Output Setup Screen
Click on the Analog Out tab so set up the optional analog output board. Three output ranges are selectable, the endpoints of which can be tied to user-specified High and Low readings.
DPM Lockouts Setup Screen
Click on the Lockouts tab to check off menu items which will no longer be accessible from the front panel of the meter. This will simplify meter operation and prevent unintended setup changes.
Meter Setup Utilities
DPM Front Panel Setup Screen
As an aid to programming the meter from the front panel when a serial connection is not available, you can return to the Main Menu and click on View > Menu. The required sequence of front panel screens will then be displayed. Click on any step in the sequence for the meaning of each digit, as illustrated for the FILtEr step. For a hardcopy, simply press on Print.
DPM Jumper Setup Screen
Specify your desired communication protocol and the serial communications bus type, which should match the jumper setup of the instrument. Select None if the PC is not connected to the instrument.
DPM Jumper Setup Screens
Click on any of the displayed plug-in boards, and you will be presented with the jumper positions and electrical connections for your selected board. This minimizes the need to refer to the printed manual.
DPM Commands Screen
This page allows you set up external input, serial communications, an analog output proportional to the display (optional), and lockouts for Laureate digital counters. The grayed out area at the top right of the screen applies to Laureate remote displays.
Graphical Output Screens (not available with Ethernet)
From the Main Menu, click on Readings if your PC is connected to the meter. A pull-down menu then offers three choices: List, Plot and Graph.
- List presents the latest readings in a 20-row by 10-column table. Press Pause at any time to freeze the display. This is one method to capture peak readings.
- Plot generates a plot of readings vs. time in seconds. It effectively turns the DPM-PC combination into a printing digital oscilloscope.
- Graph generates a histogram where the horizontal axis is the reading and the vertical axis is the number of occurrences of readings. The display continually resizes itself as the number of readings increases.
DPM Calibration Screens
Click on the Scaling tab, which provides three scalClick on the Scaling tab, which provides three scaling methods to relate the signal to the displayed reading: 1) Scale and Offset method, 2) Coordinates of two points method, and 3) Reading Coordinates of Two Points method. The last method uses actual high and low signals, and the computer will prompt you.
Frequency Meter Calibration Screen
Calibration of the quartz crystal of the Laureate frequency meter requires the input of a known frequency from a calibrator. Apply the frequency, then enter the frequency in Hertz. Calibration will be automatic, with storage of the calibration factor stored in non-volatile memory.
Laureate™ 1/8 DIN Case For Laureate Digital Panel Meters, Counters, Timers & Remote Displays
Key Features
- Meets 1/8 DIN Standard.
- Installs from front of panel.
- Short depth behind the panel: only 4" (102 mm) plus connectors.
- Understated 0.157" (4 mm) thick bezel.
- Meets NEMA 4X (IP-65) for high-pressure wawshdon when panel mounted.
- Screw clamps connectors meet VDE / IEC / UL / CSA safety standards.
- Rugged GE Lexan® housing material.
- Safety certified per EN 61010-1.
Dimensions
Maximum panel thickness: 4.5 mm (0.18")
Weight of base meter: 210 g (7.4 oz) typical (DPM, counter, timer, 6-digit remote display)
Weight of option boards: 30 g (1.0 oz) typical per board (analog output, relay output, communications)
Tightening Torque - Connectors: Screw terminal connectors: 5 lb-in (0.56 Nm)
Tightening Torque - Pawls: Digital Panel Meter Case Pawls: 5 lb-in (0.56 Nm)
Dimensioned CAD assembly drawings in EPRT, STEP, x_t. dwg, pdf file formats: Laureate-meter-case.zip (zipping prevents browser from opening CAD files as text files).
Panel Mounting
Slide the meter into a 45 x 92 mm 1/8 DIN panel cutout. Ensure that the provided gasket is in place between the front of the panel and the back of the meter bezel.
The meter is secured by two pawls, each held by a screw, as illustrated. Turning each screw counterclockwise extends the pawl outward from the case and behind the panel. Turning each screw clockwise further tightens it against the panel to secure the meter.
Turning each screw counterclockwise loosens the pawl and retracts it into its well. This position allows installed meter to be removed from their panel, or new meters to be installed in a panel. Do not remove the screws from their pawls. Doing so would cause the screw and pawl to fall off and likely get lost. Do not overtighten so as not to damage the plastic parts.
Process Signal and Ratiometric Meter Frequently Asked Technical Questions
Laureate DC meters and process meters are the same and are covered by the same Section 11 of the Laureate DPM user manual. The term “DC meter” is used for any meter that displays units of DC voltage or DC current. The term “process meter” is typically used for a DC meter that accepts an industry standard 4-20 mA or 0-10V DC signal and converts that signal to engineering units using scale and offset adjustment, also called zero and span adjustment. All Laureate DC meters are user scalable regardless of range. The ±20.000 mA DC range is used for the 4-20 mA process range.
Also called a “potentiometer follower meter,” a ratiometric metric displays the ratio of a signal voltage to an applied excitation voltage. The typical sending device is a potentiometer where a DC excitation voltage is applied across a resistive element and the signal to be measures is picked off by a contact that slides along the length of that element. Linear potentiometers are used to measure linear displacement in inches or mm. Rotary potentiometer are used to measure angular displacement in degrees or radians. For use as ratiometric meters, Laureate process meters need to be jumpered for 5 Vdc excitation and be programmed for ratiometric operation.
Laureate process meters whose model number ends with P or P1 and load cell meters whose model number end with WM1 can be used with the same types of load cells and can scale millivolt signals for display in engineering units. Limitations of the Laureate process meter compared to the load cell meter are that its resolution is limited to 10 microvolts, not 1 microvolt, and load cell connections are limited to 4 wires, not 6 wires. The slightly more expensive load cell meter is recommended for higher resolution readings.
Both signal types have been popular analog output standards for transducers and transmitters for decades. Both signals are electrically safe. 0-10V is commonly used in labs and test stations where cable runs are short and electrical noise is not a problem. 4-20 mA is used in industrial environments and for long cable runs since the current signal is active and is not affected by cable resistance or electrical noise pickup. Also, 4 mA serves as an active zero to indicate normal operation, while 0 mA would indicate a cable break or other electrical failure.
Yes they can. Laureate process meters can be jumpered for an electrically floating 24 Vdc up to 50 mA excitation output, which is electrically floating and can be used to power the transducer or transmitter that controls the 4-20 mA current signal. Please see the 2-wire wiring diagram on page 6 of the Laureate DPM user manual.
A count is a unit of resolution. For the Laureate DC and process meter, each input range is ±20,000 counts. The 0-10V process range is 0-10,000 counts using the ±20.000 Vdc range. The 4-20 mA process range is 4,000-20,000 counts using the ±20.000 mAdc range. Display counts, also called output counts, are the values to be displayed as readings. For example, a reading of 2465.7 lbs is 24657 output counts. The decimal point is set separately as a decoration.
Process meter scaling is the process of converting the meter’s input counts to a reading in engineering units, which are display or output counts. For example, if a Laureate process meter with a model number ending in P is set to the factory default input rang of 4.000-20.000 mA, scaling would allow this range to be displayed as 0-100.0 (PSI).
Under the front panel menu item “Setup,” select the “Coordinates of 2 points scaling method.” Enter Lo In, Lo Rd, and Hi In, Hi Rd. For the above example, enter 4.000 for Lo In, 0.0 for Lo Rd, and 20.000 for Hi In, 100.0 for Hi Rd.
If the process meter model number has a P suffix, this indicates that that it came with factory default scaling, which is a 4-20 mA input scaled to display 0.00 to 100.00 (%). If the process meter model meter has a P1 suffix, this means that it was ordered with custom factory scaling, which was specified as Lo In, Lo Rd, and Hi In, Hi Rd. Both the factory default P scaling and factory special P1 scaling can easily be changed by the user by selecting one of the meter’s 5 jumper selectable DC voltage ranges or 4 jumper selectable DC current ranges, and scaling the meter from the front panel, as explained in the Laureate DPM user manual.
Laureate process cell meters are modular with slots for an analog output board, a choice of relay boards, and a choice of communication boards, as illustrated in our Laureates Overview web page. These boards can be ordered installed with a new meter, but they can also be purchased separately later and be simply plugged in. The presence of a new board and the type of board are automatically sensed by the meter’s firmware or by Instrument Setup (IS) software. If you change boards, also change the model number on the meter label.
Input calibration is the process of setting the process meter in software so that absolute readings in are within specified tolerances of a recognized national standard. Electrical input calibration is required for operation of the process meter as a DC voltmeter or DC ammeter. It is also required when the meter is scaled using the scale and offset method or the coordinates of 2 points method, both of which require correct absolute DC voltage or DC current readings. Electrical input calibration is not required for the reading coordinates of 2 points scaling method, which uses actual weights or other know physical standards for calibration, not known electrical signals.
Annual calibration to NIST standards can be performed by Laurel and by some of its distributors as a service. It can also be performed by the customer using Laurel’s free Windows based Instrument Setup (IS) software. Open the Main Menu of IS software, click on Calibration in the top menu bar, and follow the prompts. An external DC voltage standard is required. Also required in the meter is a communications board, like the Laureate P/N LUSB USB interface board. Following calibration, that board can be removed and be used in another meter.
Analog output scaling is the process of converting the meter reading to an analog output, which can be user selected as 4-20 mA, 0-20 mA, 0-10V or -10 to +10V. Simply enter the process meter readings for the bottom and tops of the selected analog output range, and the output will be interpolated linearly between these two readings. Please see Section 17 of the Laureate DPM user manual.
Chances are that your meter is set for the factory default analog output, which is 4-20 mA, and is applying 10V to force a current into an open circuit. To set your meter to a 0-10V or -10 to +10V analog output, set jumpers for unipolar 0-10V or bipolar -10 to +10V operation, select the desired range and scaling, and connect to the correct analog output pins, as explained in Section 17 of the Laureate DPM user manual.
Ratiometric potentiometer follower application
In this application shown, the signal from a sliding contact voltage divider can be converted to engineering units such as position, level or percentage. By operating in a ratiometric mode, the meter automatically removes any effects caused by variations in the excitation supply. Connect excitation return to signal return, and jumper the excitation output to 5 Vdc.
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Powering two-wire transmittersThe isolated 24 Vdc, 50 mA excitation output, which is standard with all Laureate meters, is ideal for powering two-wire, 4-20 mA transmitters. The same two wires are used to apply voltage and carry the output current. Inside the meter, the 4-20 mA current is dropped across a 10 ohm resistor and sets up a 40-200 mV voltage, which is then sensed by the meter and scaled to engineering units.
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Testing with peak detectionDestructive testing is an ideal application for the Laureate strain meter. Peak readings are automatically captured at rates up to 60 per second, while the display updates at a legible 3.5 readings per second. The peak reading can be recalled at the push of a button or be transmitted via RS-232 or RS-485. The meter provides isolated 10 Vdc power for up to four (4) the strain gauges and can be scaled to read out directly in engineering units from -99,999 to +99,999.
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Custom curve linearizationThe Laureate DC meter with the Extended main board option allows exceptionally accurate custom curve linearization. For setup, up to 180 data points can be entered into a spreadsheet. The system then creates multiple non-linear spline-fit segments, which provide much better accuracy than linear segments. Illustrated, is the readout of volume of irregularly shaped tanks based on measured liquid level or pressure. Altimeters and thermistors are further applications.
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Rate from successive readingsThe Extended computer board allows the display of rate based on successive readings, for instance flow rate based on changes in liquid level or static pressure in a tank. In the above illustration, the meter displays the rate in gallons at which a horizontal tank is being emptied. The input to the meter can be nonlinear, since only the linearized readings are compared for the determination of rate.
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CAL-Analog
Certificate of Calibration
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DLS-XLOG2
XLog2 Data logging Software
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IPC
Splashproof Cover
$55.00
CON01
CON01 Connector
$75.00
CBL01
RS232 Cable for Meters
$35.00
CBL02
USB-to-RS232 Adapter Cable
$47.00
CBL04
RS232 Cable for LT Transmitters
$47.00
CBL05
USB Data Cable for Meters
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CBL06
USB-to-RS485 Adapter Cable
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CBL07
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CBL08
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6-foot Power Cable
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$47.00What Are 1/8 DIN Digital Panel Meters for Process & Ratiometric Measurement?
Digital Panel Meters are essential tools in industrial and process control environments, where precise measurement and display of data are crucial. 1/8 DIN Digital Panel Meters are compact and versatile instruments that have become a standard in the industry due to their size, reliability, and functionality. When paired with process and ratiometric measurement applications, they become even more powerful tools.
Understanding the 1/8 DIN Standard
DIN, which stands for "Deutsches Institut für Normung," is a set of standards originating from Germany that are now widely used internationally. The "1/8 DIN" refers to the size of Digital Panel Meters. The term indicates that the Digital Panel Meters occupy one-eighth of a full DIN standard panel, which typically measures 192 x 96 mm. Therefore, 1/8 DIN Digital Panel Meters have dimensions of approximately 96 x 48 mm. This compact size allows for easy integration into control panels and enclosures without taking up excessive space.
What Are Digital Panel Meters?
Digital Panel Meters are electronic devices used to display digital readings of various types of input signals, including voltage, current, temperature, pressure, and more. These Digital Panel Meters are widely used in various industries for monitoring and control purposes. The digital displays provide clear and precise readouts, which are easier to interpret than analog meters. Digital Panel Meters often come with features like programmable setpoints, alarms, and outputs, making them versatile tools for various applications.
Process Measurement: Monitoring and Control
Process measurement Digital Panel Meters are specifically designed to measure and display process variables such as temperature, pressure, flow, and level. These Digital Panel Meters are integral in maintaining and optimizing industrial processes, ensuring that they run within set parameters for safety and efficiency.
- Accuracy: Process measurement Digital Panel Meters are designed to provide highly accurate readings, which is crucial for maintaining control over industrial processes. Even slight deviations can lead to significant inefficiencies or safety hazards.
- Programmability: Many 1/8 DIN process measurement Digital Panel Meters offer programmable input types, allowing users to customize the Digital Panel Meters according to the specific needs of their applications. For instance, a single Digital Panel Meter could be used to measure temperature in one application and pressure in another.
- Alarms and Outputs: These Digital Panel Meters often include programmable alarms that trigger when the process variable exceeds or falls below set thresholds. Additionally, they can provide outputs to control other devices or systems based on the measured values.
Ratiometric Measurement: Precision in Measurement
Ratiometric measurement Digital Panel Meters specialize in displaying ratios between two input signals. This type of measurement is particularly useful in applications where relative changes are more important than absolute values, such as in strain gauges, potentiometers, or other sensors that provide ratiometric output.
- Application: Ratiometric measurement Digital Panel Meters are often used in situations where two or more variables are compared, and the relationship between them is more critical than their individual values. For example, in a pressure measurement system, comparing the pressure between two points can be more informative than knowing the absolute pressure at each point.
- Stability: Ratiometric measurement Digital Panel Meters tend to offer enhanced stability, as they reduce the influence of fluctuations in the power supply or environmental conditions by focusing on the ratio of inputs.
Combining Process and Ratiometric Measurement
In some industrial applications, there is a need to monitor both absolute process variables and relative changes simultaneously. 1/8 DIN Digital Panel Meters that can handle both process and ratiometric inputs become valuable tools in these scenarios. For example, they could be used to measure the absolute temperature in a reactor while also monitoring the ratio of temperatures between two different points within the system. This dual functionality allows for greater flexibility and precision in control systems, leading to improved process efficiency and product quality.
Advantages of 1/8 DIN Digital Panel Meters
- Compact Size: The 1/8 DIN size makes these Digital Panel Meters easy to install in crowded panels or enclosures, maximizing space efficiency.
- Versatility: With the ability to handle both process and ratiometric measurements, these Digital Panel Meters can be used across a wide range of applications, reducing the need for multiple types of instruments.
- Customization: Many 1/8 DIN Digital Panel Meters offer customizable display options, inputs, and outputs, allowing them to be tailored to specific applications.
- Ease of Use: The digital displays provide clear, precise readings that are easy to interpret, reducing the potential for human error.
Where Are 1/8 DIN Digital Panel Meters for Process & Ratiometric Measurement Used?
1/8 DIN Digital Panel Meters are versatile and compact devices widely used in industrial applications for monitoring and controlling various parameters. These Digital Panel Meters are known for their reliability, accuracy, and ease of integration into various systems, commonly used to measure parameters such as temperature, pressure, flow, voltage, and current.
- Process Monitoring
- Temperature Control: In industries like manufacturing, food processing, and HVAC (Heating, Ventilation, and Air Conditioning), temperature control is crucial. 1/8 DIN Digital Panel Meters are used to monitor temperatures accurately and provide real-time data that can be used to maintain optimal conditions in ovens, refrigeration units, and heating systems.
- Pressure Measurement: In processes involving gases and liquids, such as in chemical plants or water treatment facilities, monitoring pressure is vital for safety and efficiency. These Digital Panel Meters can display pressure readings from transducers, helping operators maintain the correct pressure levels.
- Flow Rate Monitoring: In fluid dynamics and material handling, monitoring flow rates is essential. 1/8 DIN Digital Panel Meters can be connected to flow sensors to display and track the flow of liquids or gases, ensuring processes run smoothly.
- Ratiometric Measurement
- Proportional Control: Ratiometric measurement Digital Panel Meters are used in applications where the output needs to be proportional to the input signal. For example, in dosing systems or mixing processes, 1/8 DIN Digital Panel Meters can be used to measure and display the ratio between two different inputs, ensuring precise control over the mixture.
- Torque and Load Monitoring: In mechanical systems where torque or load needs to be measured relative to another parameter (such as motor speed or force), ratiometric measurement Digital Panel Meters are used. This ensures that machinery operates within safe and efficient parameters.
- Voltage and Current Ratios: In electrical systems, ratiometric measurement Digital Panel Meters can be used to monitor and compare voltage or current ratios, providing critical information for applications like power distribution and load balancing.
Industries Using 1/8 DIN Digital Panel Meters
- Manufacturing: These Digital Panel Meters are widely used in automated manufacturing processes to monitor and control parameters such as temperature, pressure, and flow, ensuring product quality and process efficiency.
- Energy and Utilities: In power plants, water treatment facilities, and renewable energy installations, 1/8 DIN Digital Panel Meters are essential for monitoring process variables and maintaining system integrity.
- Automotive and Aerospace: In these highly regulated industries, ratiometric measurements are crucial for ensuring the safety and reliability of systems involving fuel, hydraulics, and environmental controls.
- Food and Beverage: Precise control of temperature and flow is vital in food processing, making these Digital Panel Meters invaluable for maintaining product quality and meeting safety standards.
Conclusion
1/8 DIN Digital Panel Meters for process and ratiometric measurement are essential tools across a broad range of industries. Their compact size, accuracy, and versatility make them ideal for applications where monitoring and controlling various parameters are critical. Whether it's ensuring the right temperature in a manufacturing process or maintaining the correct ratio in a chemical mixture, these Digital Panel Meters play a key role in keeping operations running smoothly and safely.
Process & Ratiometric Digital Panel Meter Frequently Asked Questions
What is a 4-20 mA process signal, and why is it used?
A 4-20 mA current loop is an industry-standard way of transmitting a process variable — pressure, temperature, flow, or level — as a proportional electrical current rather than a voltage. Because current stays constant throughout the loop regardless of wire resistance, it remains accurate over long cable runs and is largely immune to the voltage drop that would affect a similar voltage-based signal.
Why does a 4-20 mA signal start at 4 mA instead of 0 mA?
This is called a "live zero." Starting the scale at 4 mA rather than 0 mA lets the meter distinguish between a genuine zero process reading (4 mA) and a broken loop or failed transmitter (0 mA), which would otherwise look identical on a signal that started at zero.
What does zero and span adjustment mean on a process meter?
Zero and span adjustment is how a process meter is scaled to match a specific transmitter's range. Zero sets what the meter displays at the bottom of the signal range (typically 4 mA), and span sets what it displays at the top (typically 20 mA), so the meter shows the process value in real engineering units rather than raw milliamps.
What is the difference between a 2-wire and 4-wire transmitter loop?
A 2-wire transmitter is loop-powered, meaning the same two wires that carry the signal also supply its operating power. A 4-wire transmitter has a separate power connection and can typically drive a higher total loop resistance since it isn't relying on the loop itself for power, which matters when a loop includes long cable runs or several devices in series.
How does ratiometric measurement differ from a standard process input?
A standard process input measures one signal against a fixed internal reference. A ratiometric input instead measures a signal relative to its own excitation or reference voltage, so variations in the supply voltage largely cancel out. This makes ratiometric measurement well suited to sensors like potentiometers and strain-based transducers, where stability against supply fluctuations matters more than an absolute voltage reading.
Can one meter handle more than one process input type?
Many 1/8 DIN process meters are programmable for multiple input types from the same hardware — 4-20 mA, 0-10V, and ratiometric signals, for example — with the specific input type selected in software or via jumpers rather than requiring a different meter for each signal type.
Can a process meter display the difference or ratio between two separate inputs?
Meters with an extended or dual-channel main board can perform arithmetic between two input channels, displaying values such as the sum, difference, or ratio of two process signals, which is useful for applications comparing two related measurements rather than reading a single absolute value.
What outputs are available for alarming or control on a process meter?
These meters commonly support programmable relay outputs for high/low alarms, an isolated analog retransmission output, and serial communications such as RS-232, RS-485, or Ethernet with Modbus, allowing the meter to both alert operators locally and feed data to a PLC or SCADA system.
Is isolation important between the process input and the meter's outputs?
Yes, particularly in process control settings with multiple instruments sharing a panel. Isolated inputs and outputs prevent ground loops and ensure that a fault or noise source on one part of the system doesn't corrupt the process reading or damage connected equipment.
How is a process meter calibrated to match a specific transmitter?
Calibration is typically done by entering the meter reading that should correspond to the transmitter's low signal (commonly 4 mA) and its high signal (commonly 20 mA), either through front-panel pushbuttons or setup software. The meter then linearly interpolates all readings in between, so the display matches the transmitter's actual calibrated range.
Process & Ratiometric Measurement Questions From the Field
Why does my process meter show a reading that moves with the signal but never matches the correct value?
This is one of the most frequently reported 4-20 mA issues, and it almost always points to a scaling problem rather than a wiring or transmitter fault. The display reacts predictably to changes in the loop current but was never scaled to match the transmitter's actual range, so the fix is re-entering the correct zero and span values to match the transmitter's datasheet rather than replacing any hardware.
My meter reads a negative or unusually low number instead of zero — what does that mean?
Field troubleshooting guides note that if a loop-powered display reads roughly 25% of its span below its expected zero point, that's a strong sign the loop current isn't actually flowing through the meter at all, rather than the process genuinely being at a below-zero value. This usually traces back to a wiring break or the meter not being properly inserted into the current loop path.
How do I tell whether a bad reading is caused by the transmitter, the wiring, or the meter itself?
The standard field approach is to measure the actual loop current directly with a multimeter or loop calibrator in series with the loop, independent of what the meter is displaying. If the measured current is correct but the display is wrong, the issue is in the meter's scaling or configuration; if the measured current itself is wrong, the fault lies upstream in the transmitter or wiring.
Why does my system report a sensor failure alarm even though I'm measuring a valid loop current?
This has been reported in cases where an analog input card's fault threshold doesn't match what's actually expected from the transmitter — for example, a card configured to expect a raised-zero range like 0-21 mA may flag a signal as a fault even when a technician measures a seemingly valid 4+ mA at the terminals. Comparing the configured fault thresholds in the PLC or meter against the transmitter's actual datasheet range is the recommended first step before assuming the transmitter has failed.
Can two different 4-20 mA sensors reading the same physical value show different currents at the same condition?
Yes — this has been documented even between sensors that should be identical, sometimes due to a manufacturing offset, a non-standard signal range (such as 5-20 mA instead of 4-20 mA) being mistaken for standard 4-20 mA, or a factory zero/span adjustment that hasn't been matched between units. Confirming each sensor's actual datasheet range and applying the correct scaling per device resolves most of these mismatches.
Does cable length affect a 4-20 mA signal the way it affects a voltage signal?
Current loops are specifically valued in the field because they resist the voltage-drop problems that affect voltage-based signals over long wire runs — since the loop maintains a constant current regardless of wire resistance within the loop's power budget, a 4-20 mA signal generally stays accurate over runs of several thousand feet where an equivalent voltage signal would need compensation.
