The MTT MS3739IB is a wide-range input version of the plug-in ratio/bias converter, built to accept bipolar current and voltage signals that swing from -100mA to 100mA or -300V to 300V. That makes it a good fit for applications where the incoming signal is not a simple unipolar 4-20mA or 0-10V range but instead crosses zero, such as bridge outputs or bidirectional process signals, before the output needs rescaling with a ratio and a bias.
Like the standard model, its output equals the input times a settable ratio plus a settable bias, with both positive and negative gain available so the signal can be inverted as well as rescaled. Zero and span are independently adjustable, and a second isolated output is available for feeding an independent monitoring system. Like the rest of the plug-in transmitter series, the MS3739IB clips into its own socket base for fast swap-out during calibration or maintenance without disturbing the field wiring, and flexible AC or DC power plus wall or DIN rail mounting make it easy to fit into an existing panel.
| Input (Current) | -100 to 100mA |
| Input (Voltage) | -300 to 300V |
| Input Resistance | 10Ω to 1MΩ min., depending on signal type |
| Output | 0-20mA DC current or -10 to 10V DC voltage; single or dual output |
| Output Load | 750Ω max. (4-20mA single); 550Ω/350Ω max. (dual) |
| Ratio Adjustment | Positive gain 0.1 to 4.00; negative gain -0.1 to -4.00 |
| Bias Adjustment | -100% to +100%, in 1% steps |
| Accuracy | Better than ±0.2% of span (at 25°C±5°C) |
| Response Time | 85ms max. (0-90%, step input at 100%) |
| Isolation | 4-way isolation between input, output 1, output 2, and power |
| Power Supply | 100-240V AC, 24V DC, or 100-240V DC |
| Power Consumption | 6.0-7.2VA/W max. |
| 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 MS3739IB used for?
It’s the wide-range input version of the plug-in ratio/bias converter, built to accept bipolar current and voltage signals that swing from -100mA to 100mA or -300V to 300V. That makes it a good fit where the incoming signal crosses zero, such as bridge outputs or bidirectional process signals, before the output is rescaled with a ratio and a bias.
How is the MS3739IB different from the standard MS3739?
The standard MS3739 takes unipolar ranges (0-20mA to 10-50mA current, or 0-10V to ±10V voltage). The MS3739IB accepts bipolar signals that swing through zero, -100mA to 100mA or -300V to 300V, a much wider span suited to bridge or differential-type signals rather than a standard 4-20mA or 0-10V loop.
How do the ratio and bias adjustments work?
Gain is adjustable from 0.1 to 4.00 (positive) or -0.1 to -4.00 (negative, which inverts the signal), and bias from -100% to +100% in 1% steps. The output equals the input times the ratio plus the bias.
Can the MS3739IB feed two circuits at the same setting?
Yes, a dual output option is available, though output load drops from 750Ω max. on a single 4-20mA output to 550Ω/350Ω max. when running dual outputs. Check your receiving instrument’s input impedance against this before specifying dual output.
How do I know whether I need the MS3739 or the MS3739IB?
It comes down to your input signal: if it’s a standard unipolar range like 4-20mA or 0-10V, the MS3739 covers it; if your signal is bipolar and crosses zero, such as a bridge output, the MS3739IB is the right fit. Send us the input signal range and we can confirm which model you need.
Download MTT MS3739IB Slim Plug-In Ratio/Bias Converter information here
Spec Sheet: MTT_SpecSheet1_MS3739IB_Rev260_E
Manual: MTT_Manual1_MS3739IB_Rev140_E
