Specifications; Analog Input Section; Channel Configurations - Measurement Computing Measurement Advantage USB-TC User Manual

Specifications

Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.

Analog input section

Parameter
A/D converters
Number of channels
Input isolation
Channel configuration
Differential input voltage
range
Absolute maximum input
voltage
Input impedance
Input leakage current
Normal mode rejection ratio
Common mode rejection
ratio
Resolution
No missing codes
Input coupling
Warm-up time
Open thermocouple detect
CJC sensor accuracy

Channel configurations

Sensor Category
Thermocouple
Channel configuration information is stored in the EEPROM of the isolated microcontroller
Note 1:
by the firmware whenever any item is modified. Modification is performed by commands
issued over USB from an external application, and the configuration is made non-volatile
through the use of the EEPROM.
The factory default configuration is Type J.
Note 2:
Table 5-1. Generic analog input specifications
Conditions
Thermocouple
±C0x through ±C7x relative to
GND (pins 9,19,28,38)
Open thermocouple detect enabled
f 60 Hz
=
IN
f 50 Hz/60 Hz
=
IN
15 °C to 35 °C
0 °C to 70 °C
Table 5-2. Channel configuration specifications
Conditions
J, K, S, R, B, E, T, or N
5-1
Specification
Four dual 24-bit, Sigma-Delta type
8 differential
500 VDC minimum between field wiring and
USB interface
Thermocouple sensor type
±0.080 V
±25 V power on, ±40 V power off.
5 Gigohm, min.
105 nA max.
90 dB min.
100 dB min.
24 bits
24 bits
DC
30 minutes min.
Automatically enabled when the channel pair
is configured for thermocouple sensors.
The maximum open detection time is 3
seconds.
±0.25 °C typ.,
±0.5 °C max.
-1.0 to +0.5 °C max
Specification
8 differential channels
Chapter 5