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$393.00 (USA and Canada only)

Availability: In stock
SNAP 2-Ch Isolated Type B,C,D,G,N,T,R, or S Thermocouple Analog Input Module

Production Specification

The SNAP-AITM2-i provides two isolated channels, each with an input range of -50 to +50 mV, -25 to +25 mV, or type B,C,D,G,N,T,R, or S thermocouple. In addition to having two channels isolated from each other, the module is also transformer isolated and optically isolated from other modules and devices.

Part of the SNAP PAC System, the module mounts on a SNAP PAC rack with a SNAP PAC brain or rack-mounted controller. Analog, digital, and serial I/O modules can all be on the same rack. Such an I/O unit is also well suited for PC-based control or for use as intelligent remote I/O for an Allen-Bradley Logix PLC system, such as ControlLogix, MicroLogix, or CompactLogix.

Build your system in the SNAP I/O Configurator.

Input Range

From -50 mV to +50 mVDC
From -25 mV to +25 mVDC

Maximum Over Range

± 10%
(= ± 27500 counts)


2 µV from -50 mV to +50 mV
1 µV from -25 mV to +25 mV

Cold Junction Temperature Compensation

Automatic when used with SNAP brains

Input Filtering

-3 dB @ 2.4 Hz

Input Response Time
(% of span/delta V/delta time)

63.2%/31.5 mV/66 ms

Data Freshness

65 ms for +/- 50 mV
130 ms for +/- 25 mV
130 ms for B-, R-, S-, and T-type thermocouples
65 ms for C-, D-, G-, and N-type thermocouples

DC Common Mode Rejection

>-120 dB

AC Common Mode Rejection

>-120 dB @ 60 Hz

Maximum Survivable Input

±15 volts

Maximum Operating
Common Mode Voltage

250 V


0.1% (50 µV) @ 50 mV (full scale)
0.2% (50 µV) @ 25 mV (full scale)

Drift: Gain Temperature

5 µV / °C

Drift: Offset Temperature Coefficient

2 µV / °C

Thermocouple Accuracy [°C]
 From factory
 After user gain and offset commands

B, R, S    C, D, G    T, N
   ±5            ±4          ±3
   ±3            ±2          ±2


Isolation: Optical

4000 V

Isolation: Transformer

1500 V

Isolation: Channel to Channel

250 V continuous
(1500 V transient)

Power Requirements

5 VDC (±0.15 ) @ 200 mA

Input Resistance

100 megohms (each channel)

Ambient Temperature:


-20 °C to 70 °C
-40 °C to 85 °C


5-95%, non-condensing

Torque, hold-down screws

Not to exceed 1 in-lb (0.11 N-m)

Torque, connector screws

3 in-lb (0.34 N-m)

Wire size range

22 to 14 AWG

Agency Approvals




SNAP PAC System Product Guide

This document lists and describes all current Opto 22 SNAP PAC System part numbers, including PAC Project software, SNAP PAC controllers, and SNAP I/O modules of all kinds. SNAP PAC mounting racks and SNAP power supplies are also listed.

SNAP Isolated Analog Input Modules Data Sheet

The isolated analog input modules described in this document are part of Opto 22's SNAP PAC System. They provide optical isolation, transformer isolation, and channel-to-channel isolation. This data sheet covers the following part numbers:

UKCA Declaration of Conformity (EMC, LVD, RoHS)

This document is the Manufacturer's Declaration of Conformity for the products listed herein, in accordance with the rules, regulations and standards of the United Kingdom. The models cited have been tested to the essential requirements listed in the Standards section, and fully comply with the legislation as listed in UK Legislation section.

I/O Solutions for Temperature Monitoring (Chinese)

This document is written in Chinese.

This white paper describes various temperature sensors such as RTDs, thermocouples, ICTDs, thermistors, and infrared sensors, and the Opto 22 solutions for using them.

Primer: I/O Solutions for Temperature Monitoring

This primer describes various temperature sensors such as RTDs, thermocouples, ICTDs, thermistors, and infrared sensors, and the Opto 22 solutions for using them.

Opto 22 RoHS 3 Statement of Compliance - Restriction of Hazardous Substances

This document is a statement of compliance with the EU Directive 2015/863/EU, Restriction of Hazardous Substances (RoHS 3). This document lists Opto 22 products that comply with the substance restrictions of the RoHS 3 directive.

UL Approval Document

This document lists all Opto 22 part numbers that have the Underwriters Laboratory (UL) approval.

CE Declaration: Low Voltage

This document is the Manufacturer's Declaration for the listed products as mentioned in the attachment - to which this confirmation refers - that they are in accordance with the mentioned European, international and/or national standards and regulations.

CAD Drawing: SNAP I/O Module

This CAD file includes drawings that apply to most SNAP analog and digital I/O modules.

Video: SNAP PAC System Overview

This overview describes the four integrated components of the SNAP PAC system: software, controllers, brains and I/O. This hardware and software system is designed for industrial control, remote monitoring and data acquisition.

Video: Securing SNAP Module

A quick overview on securing a SNAP Module to a SNAP rack.

Video: Removing a SNAP Module

A quick overview on removing a SNAP module.

Video: I/O Solutions for Temperature Monitoring

A quick overview on I/O Solutions for temperature monitoring.

Accuracy vs Resolution

What's the difference between accuracy and resolution in analog I/O specifications? Try your own specs in the calculator.