Measurement Computing WLS-TEMP - Manual (Page 23)

23
Chapter 5
Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.
Analog input
Table 1. Generic analog input specifications
Parameter Condition Specification
A/D converters Four dual 24-bit, Sigma-Delta type
Number of channels 8 differential
Input isolation 500 VDC minimum between field wiring and
USB interface
Channel configuration Software programmable to match sensor type
Differential input voltage
range Thermocouple ±0.080 V
RTD 0 to 0.5 V
Thermistor 0 to 2 V
Semiconductor sensor 0 to 2.5 V
Absolute maximum input
voltage ±C0x through ±C7x relative to GND ±25 V power on
±40 V power off
Input impedance 5 GΩ, min
Input leakage current Open thermocouple detect disabled 30 nA max
Open thermocouple detect enabled 105 nA max
Normal mode rejection ratio f
IN
=60 Hz 90 dB min
Common mode rejection
ratio f
IN
=50 Hz/60 Hz 100 dB min
Resolution 24 bits
No missing codes 24 bits
Input coupling DC
Warm-up time 30 minutes min
Open thermocouple detect Automatically enabled when the channel pair is
configured for thermocouple sensor.
The maximum open detection time is 3 seconds.
CJC sensor accuracy 15 °C to 35 °C ±0.25 °C typ,±0.5 °C max
0 °C to 70 °C –1.0 °C to +0.5 °C max