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Panel Meters - Counters - Timers - Transmitters, 4-20 mA & Modbus - Ethernet - USB - RS485 - RS232

L40 Low-Cost, Universal Analog Input Digital Panel Meter

Jumper selectable for DC, AC, Process, Thermocouple, RTD, Thermistor, or Resistance Signals
Laurel L40A Universal Digital Panel Meter

User-selectable ranges

  • DC voltage: ±60.0 mV, ±200.0 mV, ±2.000V, ±20.00V, ±200.0V, ±400V
  • DC current: ±20.00 mA, ±5.00A
  • AC RMS voltage: 60.0 mV, 200.0 mV, 2.000V, 20.00V, 200.0V, 400V
  • AC RMS current: 20.00 mA, 5.00A AC
  • Process: 4-20 mA, 0-10V with 15V, 30 mA excitation output
  • Thermocouple types: K, J, E, N, L, C, R, S, B, T
  • RTD types: Pt100, Pt500, Pt1000, Ni100, Ni200, Ni1000
  • Thermistor types: NTC, PTC
  • Resistance: 0-5.000 kΩ, 0-50.00 kΩ
  • Potentiometer input: 500Ω to 20 kΩ
  • Frequency input: 15.0 Hz to 100.0 Hz

Standard Features

  • Universal power: 18-265V ac/dc
  • 1/8 DIN case with 3 front panel keys
  • 4 red LED digits, 14.2 mm (0.56")
  • 5 selectable LED brightness levels
  • Typical accuracy: 0.2% of full scale
  • Removable screw-clamp connectors
  • External control input


  • 1 or 2 mechanical relays, 8A, 250Vac
  • Isolated analog output
  • RS485 Modbus RTU data output
CE Mark
L40A panel meter with instrument panel

Model L40 is a low-cost, universal meter for 65 user-selectable analog input signal types and ranges. These include DC voltage and current, AC RMS voltage and current, process signals (4-20 mA, 0-10V), thermocouple (10 types, °C or °F), RTD (6 types, °C or °F), thermistors (NTC or PTC), resistance (0-5k or 0-50k ohms), and potentiometer inputs. The same meter handles all of these signal types with no need for a plug-in signal conditioner board. The meter's universal power supply accepts voltages from 18 to 265V, AC or DC, so that power can be 24 Vdc or AC power in any country. The meter conforms to the popular 1/8 DIN size standard and features four 14.2 mm (0.56") high red LED digits. The display is user scalable for input types other than temperature.L40 range selection jumpers

The base L40, as shipped by Laurel, is set up so that a 400 Vac input reads 400. To change to another signal type or range, pry off the meter faceplate, push out the electronics, and place jumpers as illustrated in the manual. The jumper positions are well labeled, and the jumpers have a large, easy-to-grasp handle. Also make software selections using front panel keys. If you want Laurel or your distributor to set jumpers and do the front panel programming for you, order the FS option.

Extensive software features add flexibility to this low cost meter. Programmable features include five levels of display brightness, min and max capture, dual scaling selectable by an external control input, a deadband around 0 for AC measurements, a moving average digital filter, a "count by" function, hysteresis for alarm operation, a user-configurable fast access menu, and selectable password protection. Further flexibility is provided by 1 or 2 optional output boards, which can be added at any time.

An Option 1 board can plug into the display board. This can be a single 8A relay board, an isolated active or passive 4-20 mA analog output board, or an isolated Modbus compatible RS485 serial data output board.

An Option 2 board can plug into the Option 1 board if installed. This is another single 8A relay board. For example, this board allows an L40 to have and analog output and a relay output, or to have two relay outputs.

L40 meter circuit boards

If only a single meter is to be stocked for a large number of applications, the low-cost L40 is your choice. While this meter does not match the high accuracy, speed and programmable features of our Laureate series, it is perfect for many panel meter applications.


DC Voltage & Current

Range Resolution Input Resistance Max Signal Accuracy
±60.0 mVdc 0.1 mV 1 MΩ 3 Vdc < 0.25% FS
±200.0 mVdc 0.1 mV 10 kΩ 30 Vdc < 0.20% FS
±2.000 Vdc 1 mV 100 kΩ 100 Vdc < 0.20% FS
±20.00 Vdc 0.01V 1 MΩ 150 Vdc < 0.20% FS
±200.0 Vdc 0.1 V 12 MΩ 800 Vdc < 0.20% FS
±400 Vdc 1 V 12 MΩ 800 Vdc < 0.20% FS
±20.00 mAdc 0.01 mA 4.7 Ω 25 mAdc < 0.15% FS
±5.00 Adc 10 mA 20 mΩ 7 Adc max 7 sec < 0.25% FS

AC RMS Voltage & Current

Range Resolution Input Resistance Max Signal Accuracy
60.0 mVac 0.1 mV 1 MΩ 3 Vac < 0.3% FS
200.0 mVac 0.1 mV 10 kΩ 30 Vac < 0.3% FS
2.000 Vac 1 mV 100 kΩ 100 Vac < 0.3% FS
20.00 Vac 0.01V 1 MΩ 150 Vac < 0.3% FS
200.0 Vac 0.1 V 12 MΩ 800 Vac < 0.3% FS
400 Vac 1 V 12 MΩ 800 Vac < 0.3% FS
20.00 mAac 0.01 mA 4.7 Ω 25 mAac < 0.5% FS
5.00 Aac 10 mA 20 mΩ 7 Aac max 7 sec < 0.5% FS

Process Signals

Range Scaling Input Resistance Max Signal Accuracy
4-20 mAdc -1999 to 9999 4.7 Ω 25 mA < 0.15% FS
0-10 Vdc -1999 to 9999 1 MΩ 25 Vdc < 0.20% FS

Platinum and Nickel RTD Temperature Probes

RTD Type Range °C Range °F Excitation Accuracy
Pt100 -200 to 700°C -328 to 1292°F < 900 µA, 2 or 3-wire < 1°C
Pt500 -150 to 630°C -238 to 1166°F < 90 µA, 2-wire < 1°C
Pt1000 -190 to 630°C -310 to 1166°F < 90 µA, 2-wire < 1°C
Ni100 -60 to 180°C -76 to 356°F < 900 µA, 2-wire < 1°C
Ni200 -60 to 120°C -76 to 248°F < 900 µA, 2-wire < 1°C
Ni1000 -60 to 180°C -76 to 356°F < 90 µA, 2-wire < 1°C

Thermocouple Temperature Probes

TC Type Range °C Range °F Accuracy
Type K -100 to 1350°C -148 to 2462°F < 3°C
Type J -100 to 1200°C -148 to 2192°F < 3°C
Type E -100 to 1000°C -148 to 1832°F < 3°C
Type N -100 to 1300°C -148 to 2372°F < 3°C
Type L -100 to 900°C -148 to 1652°F < 3°C
Type T -100 to 400°C -148 to 752°F < 3°C
Type R 0 to 1768°C 32 to 3214°F < 3°C
Type S 0 to 1768°C 32 to 3214°F < 3°C
Type B 700 to 1828°C 1292 to 3322°F < 5°C
Type C 0 to 2300°C 32 to 4172°F < 5°C

NTC Thermistors (negative temperature coefficient)

R25 Values Beta Values Resolution Accuracy
1.0 to 200.0 kΩ 2000 to 5500 1° or 0.1°, °C or °F < 1.5% of resistance

PTC Thermistors (positive temperature coefficient)

Main Series Range °C Range °F Accuracy
KTY-121 -55 to 150°C -67 to 302°F < 1°C
KTY-210, KTY-220 -55 to 150°C -67 to 302°F < 1°C


Range Resolution Bias Current Accuracy
0 to 5 kΩ 1 Ω 926 to  64 µA < 1.5% of reading
0 to 50 kΩ 10 Ω 86 to  20 µA < 1.5% of reading


Potentiometer Range Default Scaling Potentiometer Resistance Accuracy
0 to 100% 0 to 100.0 500Ω to 20 kΩ < 0.5% of FS


Frequency Range Default Resolution Signal Level Accuracy
15.0 to 100.0 Hz 0.1 Hz Same as AC range < 0.15% of Rdg

Applicable to All Signal Types

Digital readout 4 red LED digits, 7-segment, 14.2 mm (.56") digit height, 5 brightness levels
Display range -1999 to 9999
Update time 300 msec
Sensor break indication Display of "h.ovr" for overrange, "h.udr" for underrange
Indicator lamps 2 red LED alarm indicators
Universal voltage 18 to 265 Vac/dc
Power consumption < 1.5W meter only, < 2.5W meter with options
Isolation 2500 Vrms
Excitation output 5V or 15V @ 30 mA (jumper selectable)
Analog Output (M1 option for slot 1)
Output level 4-20 mA, active or passive (selectable at connector)
Maximum load 350Ω active, 700Ω passive
Scaling Zero and full scale adjustable from -1999 to +9999 counts
Accuracy < 0.5% FS
Update time 400 ms
Isolation 1000 Vdc
Relay Outputs (A1 option for slot 1 or A2 option for slot 2)
Relay type Single 3-contact relay (NC, NO, common)
Current rating 8A at 250 Vac
Isolation 2500 Vrms
RS485 (S1 option for slot 1)
Protocol Modbus RTU
Programmable addresses 1-247
Supported function code 4 = Read the register
Registers 0 = Reading value (16 bits); 1 = number of decimals (16 bits)
Error codes 0 = Function not supported; 1 = Register not accessible
Data rates 9600 or 4800 baud
Isolation 1000 Vdc
Signal Connections
Operating temperature 0°C to 50°C
Storage temperature -20°C to 70°C
For applications assistance, phone 714-434-6131 ext. 104, or email
Ordering Guide
L40 Low-Cost, 1/8 DIN, Universal Analog Input Digital Panel Meter
Click on the radio buttons to build a model number with pricing as shown below. 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
   SKU  Descriptions Price
Base meter
L40 Digital panel meter for 65 user-selectable analog signal types and ranges. Includes power from 18-265 Vac/dc. $148
Custom Setup by Vendor
  None. Meter shipped with factory default settings for 0-400 Vac input, display of 0-400.  
FS Jumper setting and front panel programming done by vendor as a service. Specify the signal type and range. For DC, AC, process and resistance signals which require scaling, specify min input, min reading, and max input, max reading. For temperature, specify 1° or 0.1° resolution and °C or °F. For NTC thermistors, specify R25 and beta. $22
Slot 1 option Board. Shipped installed in meter.
A1 Single 8A relay for Slot 1 $33
M1 Isolated, scalable 4-20 mA output $55
S1 Isolated RS485 output, Modbus RTU $55
Slot 2 option Board. Shipped installed in meter. Requires Slot 1 option board.
A2 Single 8A relay for Slot 2 $33
Add-on Options & Accessories
NL Front panel with button pads but no Laurel logo. $5
IPC Front panel cover, seals front of meter case to NEMA 4X. $44
BOX1 Wall mount polycarbonate enclosure sealed to NEMA 4X. $154
BOX2 Wall mount polycarbonate enclosure sealed to NEMA 4X, plus IPC cover. $198
CASE1 Benchtop laboratory case for one 1/8 DIN meter. $127
CASE2 Benchtop laboratory case for two 1/8 DIN meters. $127
Configured model number L40
Configured price per model $148
Quantity 1
Extended price $148
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