Laureate™ Ohmmeter for Resistance in Ohms

High accuracy & high speed for production environments, plus transmitter & control outputs
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Ohmmeter by Laurel Electronics
Features
  • Five precalibrated resistance ranges from 20.000 ohm to 200.00 kohm
  • 2.0000 Mohm resistance range with factory modification
  • 1 milliohm resolution on 20 ohm scale
  • 2, 3 or 4-wire connection with lead resistance compensation
  • Up to 60 conversions per second
  • Universal 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac power
  • Wide choice of options:
    - 2 or 4 relays, mechanical or solid state (isolated)
    - Analog output, 4-20 mA, 0-10V, or -10V to +10V (isolated)
    - Serial data I/O: Ethernet, USB, RS485, RS232 (isolated)
    - Extended version to linearize and scale nonlinear sensors
Description

The Laureate Ohmmeter is ideal for high-speed, high-accuracy resistance measurements in a production environment, such as contact resistance measurements. It is factory calibrated for five jumper selectable resistance ranges from 20 ohm to 200 kohm. Accuracy is an exceptional ±0.01% of full scale ± 2 counts. Resolution is one part in 20,000. In the 20-ohm range, resolution is 1 milliohm, making the meter suitable for contact resistance and conductance measurements. An additional 2 Mohm range is available with a factory modification.

An Extended ohmmeter version is ideal for use with nonlinear sensors whose output is a changing resistance. Extremely accurate custom curve linearization is provided curvilinear spline fits, and the reading can be scaled in software to read in user-selected engineering units of measure.

Meter connections can be via 2, 3 or 4 wires. With 4-wire hookup, 2 wires are used for excitation and two separate wires are used to sense the voltage across the resistance to be measured, thereby eliminating any lead resistance effects. With 3-wire hookup, the meter senses the combined voltage drop across the resistance to be measured plus two excitation leads. It also senses the voltage drop across one excitation lead, and then subtracts twice this voltage from the combined total. This technique effectively subtracts lead resistance if the excitation leads are the same.

All resistance ranges are digitally calibrated at the factory, with calibration factors stored in EEPROM on the signal conditioner board. This allows ranges and signal conditioner boards to be changed in the field without recalibrating the meter. If desired, the meter can easily be calibrated using external standards plus scale and offset in software.

RTD signal conditioner boardHigh read rates at up to 60 or 50 conversions per second while integrating the signal over a full power cycle are provided by Concurrent Slope (US Pat 5,262,780) analog-to-digital conversion. High read rates are ideal for high-throughput manufacturing processes. Peak and valley values are automatically captured and may be displayed via a front panel pushbutton command or a control signal at the rear connector, or be transmitted as serial data.

Designed for system use. Optional plug-in boards for communications and control include Ethernet and other serial communication boards, dual or quad relay boards, and anisolated 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 red or green LEDs. 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. All power and signal connections are via UL / VDE / CSA rated screw clamp plugs.

Multiple relay operating modes are selectable in software. One of these is band deviation setpoint operation, where a deviation limit (such as 50 counts) is set up around both sides of the setpoint. The relay closes (or opens) when the reading falls within the deviation band, and opens (or closes) when the reading falls outside of this band. This mode sets up a passband around the setpoint and is often used for component testing.

Resistance Measurement with Excitation & Lead Compensation

Ohmmeter hookup can be via 2, 3 or 4 wires to the J5 connector. The meter applies a fixed excitation current for each resistance range.

In 4-wire hookup, different pairs of leads are used to apply the excitation current and sense the voltage drop across the unknown resistance, so that the IR drop across the excitation leads is not a factor.

In 3-wire hookup, the meter senses the combined voltage drop across the unknown resistance plus two excitation leads. It also senses the voltage drop across one excitation lead, and then subtracts twice this voltage from the combined total. This technique effectively subtracts all lead resistance and compensates for ambient temperature changes if the two excitation leads are identical.

In 2-wire hookup,the meter senses the combined voltage drop across the unknown resistance and both lead wires. The voltage drop across the lead wires can be measured by shorting out the resistance during meter setup, and this voltage is then automatically subtracted from the combined total. However, changing resistance of the lead wires due to ambient temperature changes will not be compensated.

QA Application with Relay Option in Passband Mode
Deviation mode relay operation for digital panel meters and counters

A deviation limit (50 mohm in this example) is set up around both sides of a setpoint. The relay closes (or opens) when the reading falls within the deviation band, and opens (or closes) when the reading falls outside of this band. This mode sets up a passband around the setpoint and can be used for contact resistance testing.

Specifications Back to top
Range Resolution Accuracy Excitation Current
0-20.000 ohm *
0-200.00 ohm *
0-2000.0 ohm *
0-20000 ohm*
0-200.00 kohm *
0-2.0000 Mohm **
1 mohm
10 mohm
100 mohm
1 ohm
10 ohm
100 ohm
±0.01% of range
± 2 counts
5 mA
500 µA
50 µA
5 µA
500 nA
500 nA

* Jumper-selectable, precalibrated range.
** Factory-set fixed range

Display
Readout
Color
Indicators
5 digits, 7-segment, 14.2 mm (.56")
Red or green LED
2 red LED lamps
Accuracy
Accuracy at 25°C
Span tempco
±0.01% of range ± 2 counts
±0.003% of reading/°C
Electrical
Connection
Max applied voltage
Overvoltage protection
Open sensor indication
2, 3 or 4-wire
100 mV
125 Vac
Flashes full-scale
A-to-D Conversion
Technique
A-to-D Rate
Output Update
Display Update
Concurrent Slope (Pat 5,262,780)
60/s at 60 Hz, 50/s at 50 Hz
56/s at 60 Hz, 47/s at 50 Hz
3.5/s at 60 Hz, 3/s at 50 Hz
Power
Voltage, standard
Voltage, optional
Frequency
Power Isolation
85-264 Vac or 90-300 Vdc (DC operation not ETL certified)
12-32 Vac or 10-48 Vdc
DC or 47-63 Hz
250V rms working, 2.3 kV rms per 1 min test
Analog Output (optional)
Output Levels
Current compliance
Voltage compliance
Scaling
Resolution
Isolation
4-20 mA, 0-20 mA, 0-10V, -10 to +10V (jumper selectable)
2 mA at 10V ( > 5 kOhm load)
12V at 20 mA ( < 600 Ohm load)
Zero and full scale adjustable from -99999 to +99999
16 bits (0.0015% of full scale)
250V rms working, 2.3 kV rms per 1 min test
Relay Outputs (optional)
Relay Types

Current Ratings

Output common
Isolation
2 Form C contact relays or 4 Form A contact relays (NO) 2 or 4 Form A, AC/DC solid state relays (NO)
8A at 250 Vac or 24 Vdc for contact relays
120 mA at 140 Vac or 180 Vdc for solid state relays
Isolated commons for dual relays or each pair of quad relays
250V rms working, 2.3 kV rms per 1 min test
Serial Data I/O (optional)
Board Selections

Protocols
Data Rates
Digital Addresses
Isolation
Ethernet, Ethernet-to-RS485 server, USB, USB-to-RS485 server, RS485 (dual RJ11), RS485 Modbus (dual RJ45), RS232.
Modbus RTU, Modbus ASCII, Laurel ASCII protocol
300 to 19200 baud
247 (Modbus), 31 (Laurel ASCII),
250V rms working, 2.3 kV rms per 1 min test
Environmental
Operating Temp.
Storage Temp.
Relative Humidity
Protection
0°C to 60°C
-40°C to 85°C
95% at 40°C, non-condensing
NEMA-4X (IP-65) when panel mounted
Ordering Guide Back to top
Laureate Panel Meter for Resistance Measurement in Ohms
Click on the radio buttons to build a model number with pricing (shown below the Ordering Guide). Prices are in US dollars and do not include shipping or duty charges (export sales).
Please see our explanations and limitations applicable to pricing and online orders Prices shown are in US Dollars and are Laurel's manufacturer's suggested retail price (MSRP) in the USA. Orders are processed manually, not directly by our shopping cart system. You don't have to supply credit card information when placing an online order.

North American Orders. Laurel does not sell factory-direct in the USA or Canada. Online sales orders are filled through distribution. During the ordering process, you will have the chance to select an authorized Laurel distributor, or you can ask Laurel to refer you to a distributor. The distributor will then contact you to quote shipping, tax and duty (where applicable), and arrange for payment.

International Orders. If your ship-to address indicates that you are outside of the USA or Canada and Laurel has a distributor in your country, we will forward your order to that distributor for follow-up. If Laurel does not have a distributor in your country, we will email you an order acknowledgment and a pro forma invoice which states the product price, shipping charges, and wire transfer information, which includes a $25 bank wire transfer fee.

Questions about your order? Please email your distributor or sales@laurels.com

Configured model number L10000R1
Configured price per model $230
Quantity 1
Extended price $230
Quantity
DPM Type
L Digital Panel Meter
$230
Main Board
1 Standard Main Board, Green LEDs
2 Standard Main Board, Red LEDs
3 Extended Main Board, Green LEDs
4 Extended Main Board, Red LEDs
$0
$0
$40
$40
Note: Extended allows custom curve linearization for scaled readings from a changing resistance.
Power
0 Isolated 85-264 Vac or 90-300 Vdc
1 Isolated 12-32 Vac or 10-48 Vdc
$0
$30
Relay
Output
(isolated)
0 None
1 Two 8A Contact Relays
2 Two 120 mA Solid State Relays
3 Four 8A Contact Relays
4 Four120 mA Solid State Relays
$0
$80
$55
$100
$75
Analog
Output
(isolated)
0 None
1 Isolated 4-20 mA, 0-20 mA, 0-10 V, -10 to +10V
$0
$90
Digital
Interface
(isolated)
0 None
1 RS232
2 RS485(dual RJ11 connectors)
4 RS485 Modbus (dual RJ45 connectors)
5 USB
6 USB-to-RS485 device server
7 Ethernet
8 Ethernet-to-RS485 device server
$0
$60
$80
$90
$60
$100
$120
$150
Resistance
Range
R1 0-20 ohms
R2 0-200 ohms
R3 0-2 kohms
R4 0-20 kohms
R5 0-200 kohms
R6 0-2 Mohms (factory special fixed range)
$0
$0
$0
$0
$0
$25
Add-on
Options
CBL01  RS232 cable, RJ11 to DB9, 7 ft. Connects RS232 ports of meter
and PC.
CBL02 USB to RS232 adapter cable. Combination of CBL02 and CBL01
connects meter RS232 port to PC USB port. Combination of CBL02 and
CBL04 connects transmitter RS232 terminals to PC USB port.
CBL03-1 6-wire data cable, RJ11 to RJ11, 1 ft. Used to daisy chain meters
via RS485.
CBL03-7 6-wire data cable, RJ11 to RJ11, 7 ft. Used to daisy chain meters
via RS485.
CBL05 USB cable, A-B. Connects USB ports of meter and PC.
CBL06  USB to RS485 adapter cable, half duplex, RJ11 to USB. Connects
meter RS485 port to PC USB port.
NL  Meter Lens with Button Pads but no Laurels Logo
BL  Meter Lens without Button Pads or Laurels Logo
IPC Splash-proof Cover
BOX1 NEMA-4 Enclosure
BOX2 NEMA-4 Enclosure plus IPC
$19
$39
$8
$8
$15
$39
$5
$5
$40
$140
$180


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