The MTT MS3103 is a terminal block type millivolt isolator with two independent, isolated outputs. It accepts a -200mV to 200mV input, with span from 5mV to 400mV, 1MΩ min input resistance, and a maximum continuous input of 30V DC.
Output 1 and output 2 are independently configurable to current 0~20mA (span 4~20mA) or voltage -10 to 10V (span 10mV to 20V) – useful when one signal needs to feed a PLC and a second, separate signal needs to feed a recorder or indicator at the same time. Zero and span are each adjustable by about ±5% of span, with accuracy better than ±0.1% of span at 25°C±5°C and temperature effect better than ±0.2% of span per 10°C change. Response time is 160ms max (0 to 90%), with CMRR of 100dB min (500V AC, 50/60Hz).
There is 5-way isolation between input, output 1, output 2, power, and ground, with dielectric strength of 2000V AC for 1 minute – this is what keeps a low-level millivolt reading clean of ground loops and noise over a long cable run.
Power supply is flexible: 100-240V AC, 24V DC, or 110V DC, drawing 6.5VA (AC), 1.6W (24V DC), or 2.5W (110V DC). The unit mounts on DIN rail with M3.5 screw terminals, measuring W49.8 × H102.0 × D40.0mm and weighing under 140g. It is rated for -5 to 55°C operation (5-90% RH non-condensing) and -10 to 60°C storage.
| Input Range | -200mV to 200mV, span 5mV to 400mV |
| Input Resistance | 1MΩ min. |
| Allowable Input Voltage | 30V DC max., continuous |
| Output 1 & 2 | Current 0-20mA (span 4-20mA) or voltage -10 to 10V (span 10mV to 20V) |
| Zero / Span Adjustment | Approx. ±5% of span each |
| Accuracy | Better than ±0.1% of span (at 25°C±5°C) |
| Temperature Effect | Better than ±0.2% of span per 10°C change |
| Response Time | 160ms max. (0 to 90%) |
| CMRR | 100dB min. (500V AC, 50/60Hz) |
| Power Supply | 100-240V AC, 24V DC, or 110V DC |
| Power Consumption | 6.5VA (AC), 1.6W (24V DC), 2.5W (110V DC) |
| Isolation | 5-way isolation between input, output 1, output 2, power, and ground |
| Dielectric Strength | 2000V AC for 1 minute |
| Enclosure / Mounting | DIN rail mounting, M3.5 screw terminal |
| Dimensions | W49.8 × H102.0 × D40.0 mm |
| Weight | 140g max. |
| Operating Temperature | -5 to 55°C, 5-90% RH non-condensing |
| Storage Temperature | -10 to 60°C |
Frequently asked questions
What is the MS3103 used for?
It converts a low millivolt signal, such as from a load cell or strain gauge, into two fully independent, isolated DC outputs, so a control system and a separate alarm or monitor can both read the same measurement.
Can the MS3103 be used with AC power instead of 24V DC?
Yes, it accepts 100 to 240V AC, 24V DC, or 110V DC, so it fits panels that don’t have a clean 24V DC bus available.
What’s the difference between the MS3103 and the MS3003?
The MS3003 has a single isolated output and runs on 24V or 12V DC only. The MS3103 adds a second, independently isolated output and accepts AC or DC power, so use the MS3103 when you need to feed two separate systems from one sensor or only have AC power available.
Does the MS3103 need a separate power supply?
Yes, it needs 100 to 240V AC, 24V DC, or 110V DC to operate — it is not loop-powered.
Download MTT MS3103 Terminal Block Type Millivolt Isolator information here
Datasheet: MTT MS3103 Spec Sheet (PDF)
Manual: MTT MS3103 User’s Manual (PDF)
