Universal Strain Gauge Bridge Input Transmitter

The STRAIN universal strain gauge bridge input transmitter can be used to convert any standard 4-wire bridge signal into isolated 4-20mA or voltage outputs.

Isolated bridge Excitation Voltage
User configurable mA or Voltage output
1500V 3-port Isolation
DC or AC Supply Options

Product Description

The STRAIN universal strain gage bridge input transmitter is suitable for use with the majority of strain gauges, load cells and pressure transducers. The unit provides a high stability excitation voltage which is isolated from both the high level output and the power supply.

Front panel push buttons allow non-interactive adjustment of the output zero and span settings. This is espacially useful for the initial calibration and set-up of the bridge and measuring system.

The output required may be user-reconfigurable using internal switches or requested at point of order. The options include 0-10V dc, 0-20mA, and 4-20mA. It has two power supply options, operating either from a 10 to 36Vdc supply or 90 to 264Vac supply.

The unit is housed in a 12.5mm DIN rail mounted enclosure, and also has a remote calibration feature which can be used with any bridge fitted with a calibration resistor.

Front panel mounted zero and span potentiometers can be used for in-field adjustment, used in conjunction with the output monitoring pins which allow the output to be measured without breaking the current loop.

Power supply options are either 12-36Vdc or 90-262Vac.

Two versions are available, the STRAIN-6 with a 12-36Vdc supply or the STRAIN-3 with a 90-264 Vac supply.

Product Types

STRAIN-6

SKU ID: s1-strain-0001
New Part No: II-STRAIN-6-AA-J-000
Old Part No: II-STRAIN-JJ-6-00-00
Input Types: 0-25mV…0-1200mV, unipolar or bipolar, switch selectable
Input Sensor Supply: 10Vdc
Output Types: 4-20mA, 0-20mA, 0-10mA, 2-10mA, 2-10V, 0-10V, 0-5V, 1-5V – mA source/sink, sqrt extraction, switch selectable
Power Supply: 12-36Vdc, typical 24Vdc, 12-32Vac
Isolation: Full 3-Port
Installation Type: DIN Rail TS35
Electrical Connections: Screw clamp with pressure plate

STRAIN-3

SKU ID: s1-strain-0002
New Part No: II-STRAIN-3-AA-J-000
Old Part No: II-STRAIN-JJ-3-00-00
Input Types: 0-25mV…0-1200mV, unipolar or bipolar, switch selectable
Input Sensor Supply: 10Vdc
Output Types: 4-20mA, 0-20mA, 0-10mA, 2-10mA, 2-10V, 0-10V, 0-5V, 1-5V – mA source/sink, sqrt extraction, switch selectable
Power Supply: 90-264Vac
Isolation: Full 3-Port
Installation Type: DIN Rail TS35
Electrical Connections: Screw clamp with pressure plate

Pre-configured Millivolt Input Signal Converters

Choose a pre-configured STRAIN which is set-up for a specific fixed millivolt range input and output signal:

0 to 100 millivolts signal converters

Signal converters for 0 to 100 mV scale inputs & outputs.

0 to 50 millivolts signal converters

Signal converters for 0 to 50 mV scale inputs & outputs.

0 to 30 millivolts signal converters

Signal converters for 0 to 30 mV scale inputs & outputs.

0 to 20 millivolts signal converters

Signal converters for 0 to 20 mV scale inputs & outputs.

Product Help

1 to 3 mV/V load cells

Would we be able to use this signal converter to generate a 0 to 10 volt output signal on a load cell with a 1 to 3 mV/V sensitivity, for example a 2.96 mV/V load cell will will provide 29.6 millivolt signal at full load when excited with 10 volts?

Yes, as standard the sensor bridge excitation voltage for the mV input will be set to a fixed 10Vdc to provide a stable 0 to 30 mV input.

It will be custom calibrated for a 0-30mV input to 0-10Vdc output, so any deviation between sensors will require the operator tweak the calibration of each STRAIN device e.g. 0…29.6 mV to 0…10Vdc.

Two load cell inputs to one output

Can this millivolt signal converter accept two load cell mV inputs and return a single output?

The STRAIN is a single input device, but it is common to connect up two or more load cells into a parallel configuration which will produce a single averaged output for all the load cells. The connecting together of the load cells into a parallel configuration is simplified by using what is called a ‘load cell junction box’ between the load cells and a signal conditioning module such as the STRAIN.

Signal conversion accuracy

What sort of error would the unit give at say 50% of input range?

The signal conversion error will be within 0.1% full scale at room temperature.

4-20mA or 0-10Vdc DAC input

Our DAQ system can accept 4-20mA or 0-10Vdc signals, will this strain gauge input converter provide one of these signals as the output?

Both are possible, you can select either 4-20ma or 0-10vdc following the instructions in the manual, or you can request this to be setup in the factory if you specify the configuration required when ordering.

Power supply version differences

Any advantages of using either the 240Vac or 28Vdc version?

There is no other differences between the -6 and -3 versions other than the required power supply.

6mV/V load cell compatibility

We have two two tension type load cells with 6mV/V span sensitivity and 100k lbs range, and the excitation supply voltage currently applied is 10vdc, will this signal converter work with these load cells?

Yes, an input range of 0-60mV input with a 10Vdc supply will be fine. There is a bridge excitation voltage available also for powering the load cells if you need it, which is set to 10Vdc as standard.

2 load cells with 2KΩ output resistance in parallel

We are planning to connect 2 load cells in parallel. Load cell output resistance will be 2000 ohms for both load cells, and the output signal will be 2mV/V, will the STRAIN work with this set-up?

Yes the STRAIN will work the characteristics and configuration you have described.

Load cell mV signal to 4-20mA output

We are planning to connect a load cell output (mv/V) to this device and require a 4-20mA output. Also we need fine tuning pots to calibrate the output signal?

The STRAIN is calibration by using push buttons on the front panel to fine tune, and internal switches for coarse range adjustment.

SKU ID: s1-strain-0003
New Part No: II-STRAIN-6-AA-A-000
Input Types: 0-25mV…0-1200mV, unipolar or biploar, switch selectable
Input Sensor Supply: 10Vdc
Output Types: 4-20mA – mA source/sink, sqrt extraction, switch selectable
Power Supply: 12-36Vdc, typical 24Vdc, 12-32Vac
Isolation: Full 3-Port
Installation Type: DIN Rail TS35
Electrical Connections: Screw clamp with pressure plate

Three load cells connected in parallel

I have three load cells connected in parallel, and I need a transmitter which will accept the combined output from all four load cells and convert it to an analogue output signal which will be fed into the analogue input module of my PLC. Each load cell has a rated output of 3mV/V at full scale?

The STRAIN is a universal converter for strain gauge output based devices that have a millivolt output, which is the typical output type for a load cell. So you will be able to configure the STRAIN to match the output characteristics of your load cells.

If each load cell has a 0-30mV output for a 10 volt excitation, then the output of all 3 load cells in parallel will be 0-10mV or 1mV/V, which is within the specification parameters of the STRAIN.

Bipolar ±50mVdc input to ±4Vdc output converter

I need a signal converter that will accept a +/-50 mVoltdc and gives a +/-4Vdc output?

The STRAIN-DUAL (dual output version of the STRAIN millivolt input converter) with some custom modification, will allow you to convert a bipolar +/-50mV input to a bipolar +/-4Vdc output. Both outputs would be set-up as 0-20mA with one inverted, and then feed both into a 500Ω resistor, and then adjust the output to give +/-4 Vdc.

SKU ID: s1-straindual-0001
Part No: II-DCON-STRAIN-6-AA-JJ-000
Input Types: 0-25mV…0-1200mV, unipolar or bipolar, switch selectable
Input Sensor Supply: 10Vdc
Output Types: 4-20mA, 0-20mA, 0-10mA, 2-10mA, 2-10V, 0-10V, 0-5V, 1-5V – mA source/sink, sqrt extraction, switch selectable
Power Supply: 16-36Vdc, typical 24Vdc, 18-32Vac
Isolation: Full 3-Port
Installation Type: DIN Rail TS35
Electrical Connections: Screw clamp with pressure plate
Special Option: +/-50mV input, +/-4Vdc output

Bridge supply & connections

Looking at the product manual I can’t find a section on setting up bridge supply, do you use connection 3 & 6 for the bridge supply, and how do you change bridge supply voltage?

It is connection 3&6 that is used, but the excitation voltage is factory set, usually at 10Vdc.

2.5mV/V Gefran sensor

I want to convert a 2.5 mV/V Gefran sensor to a 4-20 ma signal?

Yes you can use the STRAIN to convert your Gefran sensor, you can select an input of 0-25mV and utilise the 10 volt dc internal sensor power supply to operate the sensor without needing to use of any other electronics.

2mV/V @10V to 0…10mA conversion

I’m looking for a device that will convert a bridge out signal of 2mV/V with a bridge excitation of 10 Vdc to a 0-10mA output signal?

We would the suggest the following STRAIN configuration to provide a 0…20mV to 0 to 10mA signal conversion:

SKU ID: s1-strain-0004
Input Types: 0 to 20mV
Input Sensor Supply: 10Vdc
Output Types: 0-10mA source/sink
Power Supply: 90-264Vac
Isolation: Full 3-Port
Installation Type: DIN Rail TS35
Electrical Connections: Screw clamp with pressure plate

Solar irradiance sensor with 0-75mV output

I need an amplificator that will accept an input signal from a solar irradiance sensor of min 0 mV & max 75mV and has an output signal of min 0V max 10V or 4-20mA so that it can be sent to a plc input?

We would suggest the STRAIN which can be set up to accept a range of millivolt inputs which includes 0-75mV, and convert this to an amplified 0-10 volts or 4-20 milliamp current output. The s1-strain-0001 will work from a low voltage supply ac/dc, and the s1-strain-0002 will work from high voltage mains ac.

Universal Strain Gauge Bridge Input Transmitter – STRAIN