Measurement Computing WEB-TEMP - Manual (Page 29)

29
Chapter 6
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
power supply input.
Channel configuration Software programmable to match sensor type
Differential input voltage range Thermocouple ±0.080 V
RTD 0 V to 0.5 V
Thermistor 0 V to 2 V
Semiconductor sensor 0 V to 2.5 V
Absolute maximum input
voltage ±C0x through ±C7x relative to
AGND ±25 V (power on)
±40 V (power off)
Input impedance 5 GΩ (power on)
1 MΩ (power off)
Input leakage current Open thermocouple detect disabled 30 nA max
Open thermocouple detect enabled 105 nA max
Common mode rejection ratio f
IN
= 60 Hz 100 dB min
ADC resolution 24 bits
ADC 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 –0.75 °C to 0.5 °C max
0 °C to 55 °C –1.5 °C to 1.25 °C max