© 2001–2014 Opto 22. All rights reserved. Dimensions and specifications are subject to change. Brand or product names used herein are trademarks or registered trademarks of their respective companies or organizations.
Specifications
Part Number Description
SNAP-AITM-8
SNAP-AITM-8-FM
8-channel B, C, D, E, G, J, K, N, R, S,
or T thermocouple or -75 mV to
+75 mV, 50 mV to +50 mV, or 25 mV
to +25 mV input
Input Range
From -75 mV to +75 mV
From -50 mV to +50 mV
From -25 mV to +25 mV
Over-Range Limits
From -82.5 to +82.5 mV (+/-75 mV range)
From -55 to +55 mV (+/-50 mV range)
From -27.5 to +27.5 mV (+/-25 mV range)
Resolution
3 microvolts from -75 mV to +75 mV
2 microvolts from -50 mV to +50 mV
1 microvolts from -25 mV to +25 mV
Cold Junction Temperature
Compensation
Automatic when used with SNAP I/O
processors
Input Filtering -3 dB @ 5 Hz
Data Freshness (Max) 2.25 s
DC Common Mode
Rejection
>-120 dB
AC Common Mode
Rejection
>-120 dB @ 60 Hz
Maximum Survivable Input ±15 volts
Max Operating Common
Mode Voltage
250 V
Accuracy at Full Scale
0.1% (75 microvolts) @ 75 mV
0.1% (50 microvolts) @ 50 mV
0.2% (50 microvolts) @ 25 mV
Drift: Gain Temperature
Coefficient
5 microvolts / °C
Drift: Offset Temperature
Coefficient
2 microvolts / °C
Thermocouple Accuracy [°C] E, J, K B, R, S C, D, G T, N
From factory ±2.0 ±5 ±4 ±3
After user gain and offset
commands
±0.5 ±3 ±2 ±2
Isolation 1500 V
Power Requirements 5 VDC (±0.15) @ 200 mA
Input Resistance 100 Megohms (each channel)
Ambient Temperature:
Operating
Storage
0 °C to 70 °C
-40 °C to 85 °C
Torque, hold-down screws 4 in-lb (0.45 N-m)
Torque, connector screws 3 in-lb (0.34 N-m)
Agency Approvals
SNAP-AITM-8: UL, CE, RoHS, DFARS
SNAP-AITM-8-FM: FM, CE, RoHS,
DFARS
Warranty Lifetime
SNAP-AITM-8 and SNAP-AITM-8-FM
Thermocouple Polarity and Range
Type - + Range
B RED GRAY +42° C to +1,820 °C
C, D, G RED WHITE 0° C to +2,320 °C
E RED PURPLE -270°C to +1,000 °C
J RED WHITE -210°C to +1,200 °C
K RED YELLOW -270°C to +1,372 °C
N RED ORANGE -270° C to +1,300 °C
R, S RED BLACK -50° C to +1,768 °C
T RED BLUE -270° C to +400 °C
NOTE: For best accuracy, wire all points before
calibrating, and short all unused channels.
The SNAP-AITM-8-FM is Factory Mutual approved.
Millivolt Thermocouple Source
0
1
C
2
3
C
4
5
C
6
7
C
+
+
–
–
+
+
––
+
+
–
–
+
+
––
Common terminals are connected internally.
Description
The SNAP-AITM-8 and SNAP-AITM-8-FM modules
provide eight channels of analog to digital conversion.
Each channel on the module can be configured for -75
mV DC to +75 mV DC, -50 mV DC to +50 mV DC, -25
mV DC to +25 mV DC, or for type B, C, D, E, G, J, K, N, R,
S or T thermocouple operation.
Since all inputs share the same reference terminal, use
isolated probes for thermocouple inputs. See the
dimensional diagram on page 37.
