The MTT MS3739 is a slim plug-in ratio/bias converter that rescales a DC input signal by a settable multiplier and adds a settable offset, giving an output equal to the input times a ratio plus a bias. That combination makes it useful anywhere a signal needs rescaling to match a different range, needs inverting for a control action, or needs a fixed offset applied, such as adapting a transmitter’s span to a controller calibrated differently, or converting a direct-acting signal into a reverse-acting one.
Both ratio and bias are independently adjustable across a wide range, giving fine control over the final output shape. Like the rest of the plug-in transmitter series, the MS3739 clips into its own socket base for fast swap-out during calibration or maintenance without disturbing the field wiring, and a second isolated output is available for feeding an independent monitoring system. Flexible AC or DC power plus wall or DIN rail mounting make it easy to fit into an existing panel.
| Input (Current) | 0-20mA to 10-50mA DC ranges |
| Input (Voltage) | ±10V to 0-10V DC ranges |
| Input Resistance | 10Ω to 1MΩ, depending on signal type |
| Output | 0-20mA or 4-20mA DC current; 10mV to ±10V DC voltage; single or dual output |
| Output Load | 750Ω max. (single); 350-550Ω (dual) |
| Ratio Adjustment | ±0.1 to ±4.00, in 0.01 increments |
| Bias Adjustment | -100% to +100%, in 1% steps |
| Accuracy | Better than ±0.2% of span (at 25°C±5°C) |
| Temperature Effect | ±0.15% of span per 10°C change |
| Response Time | 85ms max. (0-90%, step input) |
| Isolation | 4-way isolation between input, output 1, output 2, and power |
| Power Supply | 24V DC, 100-240V AC, or 100-240V DC |
| Dimensions | W29 × H86 × D125mm |
| Weight | 120g max. (main unit), plus 80g max. socket |
| Mounting | Wall or DIN rail mounting |
| Terminals | M3.5 screw terminals |
| Operating Temperature | -5 to 55°C |
| Operating Humidity | 5 to 90% RH, non-condensing |
Frequently Asked Questions
What is the MTT MS3739 used for?
It’s a slim plug-in ratio/bias converter that rescales a DC input signal by a settable multiplier (ratio) and adds a settable offset (bias), giving an output equal to input times ratio plus bias. It’s used to match a transmitter’s span to a controller calibrated on a different range, invert a signal for reverse-acting control, or apply a fixed offset, without swapping out the field instrument.
How do the ratio and bias adjustments work?
Ratio is adjustable from ±0.1 to ±4.00 in 0.01 increments, and bias from -100% to +100% in 1% steps, both set via front-panel controls. A negative ratio inverts the signal (direct-acting to reverse-acting), while the bias shifts the whole output up or down independent of the ratio.
What input and output signal types does it accept?
Input accepts either current (0-20mA to 10-50mA DC ranges) or voltage (±10V to 0-10V DC ranges), and output can be current (0-20mA or 4-20mA DC) or voltage (10mV to ±10V DC), single or dual. Tell us the input and output combination your loop needs and we can confirm.
Can the MS3739 feed two circuits at the same setting?
Yes, a dual output option is available, though output load drops from 750Ω max on a single output to 350-550Ω when running dual outputs. Check your receiving instrument’s input impedance against this before specifying dual output.
How do I know if the MS3739 is right for my application?
If you need to rescale, invert, or offset a DC signal between two instruments with different ranges or actions, the MS3739 is built for that. Send us the input/output signal types and the ratio/bias you need and we can confirm before you order.
Download MTT MS3739 Slim Plug-In Ratio/Bias Converter information here
Spec Sheet: MTT_SpecSheet1_MS3739_Rev290_E
Manual: MTT_Manual1_MS3739_Rev160_E
