The MTT MS3701 is a slim plug-in thermocouple signal conditioner, mounted on a plug-in base socket for quick swap-out without rewiring. It accepts all 8 standard thermocouple types – K, E, J, T, B, R, S, and N (temperature range depends on type, e.g. Type K: 0-1350°C) – with 1MΩ min input resistance (with or without power) and cold junction compensation error of ±0.5°C max (25°C±15°C).
Output is 0~20mA DC, 4~20mA DC, or 10mV to 20V DC, available as a single output or an isolated dual output, with 4-way isolation between input, output 1, output 2, and power. Power sensitivity is better than ±0.1% of span, and overall accuracy is better than ±(0.1% of span + 0.5°C + linearity error). Response time is 160ms max (0-90%), with CMRR of 100dB minimum.
Insulation resistance is 100MΩ minimum at 500V DC, with dielectric strength of 2000V AC for one minute. The unit mounts on wall or DIN rail via a plug-in socket base, with M3.5 screw terminals. Power supply is flexible: 100-240V AC (50/60Hz), 24V DC ±10%, or 100-240V DC.
Main unit weighs up to 120g and the socket up to 80g, with overall dimensions of 29mm × 86mm × 125mm. It is rated for -5 to 55°C ambient operation (-10 to 60°C storage) and 5-90% RH non-condensing.
| Input Types | Thermocouple types K, E, J, T, B, R, S, N (temperature range depends on type, e.g. Type K: 0-1350°C) |
| Input Resistance | 1MΩ minimum, with or without power |
| Cold Junction Compensation Error | ±0.5°C maximum (25°C±15°C) |
| Output | 0-20mA DC, 4-20mA DC, or 10mV to 20V DC (single or isolated dual output) |
| Isolation | 4-way isolation between input, Output 1, Output 2, and power |
| Power Supply | 100-240V AC (50/60Hz), 24V DC ±10%, or 100-240V DC |
| Power Sensitivity | Better than ±0.1% of span |
| Accuracy | Better than ±(0.1% of span + 0.5°C + linearity error) |
| Response Time | 160ms maximum (0-90%) |
| CMRR | Minimum 100dB |
| Insulation Resistance | 100MΩ minimum at 500V DC |
| Dielectric Strength | 2000V AC for one minute |
| Dimensions (W x H x D) | 29mm x 86mm x 125mm |
| Weight | Main unit up to 120g; socket up to 80g |
| Mounting | Wall or DIN rail mounting, plug-in socket base |
| Terminals | M3.5 screw terminals |
| Operating Temperature | -5 to 55°C ambient (storage: -10 to 60°C) |
| Operating Humidity | 5-90% RH, non-condensing |
Frequently Asked Questions
What is the MS3701 used for?
It reads a thermocouple signal, applies cold junction compensation and linearization, and converts it into a standard DC output signal for a PLC, recorder, or indicator.
Can the MS3701 be used with AC power instead of 24V DC?
Yes. The MS3701 accepts 100-240V AC, 24V DC, or 100-240V DC, so it can be powered directly from panels that don’t have a dedicated 24V DC supply.
What’s the difference between the MS3701 and a terminal block type thermocouple transmitter?
The MS3701 is a slim plug-in module that mounts on its own socket base, so it can be unplugged and swapped for calibration or maintenance without touching the field wiring. A terminal block type unit has the wiring terminals built into the same housing as the electronics.
How do I know which thermocouple type to specify for the MS3701?
Check the sensor’s type designation (K, E, J, T, B, R, S, or N) and confirm the temperature range you need to measure. If you’re not sure, send us the sensor’s nameplate details or datasheet and we’ll confirm the right configuration.
Download MTT MS3701 Thermocouple Signal Conditioner (Plug-in Base Socket) information here
Datasheet: MTT_SpecSheet_MS3701_Rev310_E
Manual: MTT_Manual_MS3701_Rev170_E
