Casella CEL Sensus data logger unit - Manual (Page 39)

13. SPECIFICATION
13.1 Channel Information
Analog Channels:
12 differential analogue channels, each programmable as 2
independent single-ended channels, to give 12/24 from the main
connector panel.
4 differential analogue channels, each programmable as 2
independent single-ended channels, to give 4/8 from the expansion
port.
Numbers of differential and single-ended channels can be freely
mixed, up to the maximum number of channels available (16/32)
Input voltage ranges (measured resolution):
±2.5 V (±150 µV)
±250 mV (±24 µV)
±25 mV (±15 µV)
16-bit analogue to digital converter approx 20 ms per sample.
Switched (multiplexed) 13.8 V supply for sensor excitation.
Switched (multiplexed) 200 µA current source for sensor excitation.
Resistance measurements up to 12 kΩ . Suitable for 100 R PRTD
temperature sensors to 0.1% resolution.
Thermocouple interface under development.
Counter channels:
4 counter channels.
2 high speed and 2 medium speed.
Each channel can measure either accumulated count or frequency.
Input range:
Pulse count: 32-bit count, over scan period, logging
period or 24 hours.
Frequency: In excess of 100 kHz (high speed counter),
3 kHz (medium speed).
Inputs are 5 V logic compatible into Schmitt buffers (for slow edged
signals).
Medium speed counters continue to function when logger is in
power save (sleep) mode, high speed counters only function when
logger in full power mode.
Digital Channels:
Available via analogue channels (number of channels determined by
available analogue channels)
Specification SENSUS Digital Data Logger -
Users Handbook
Page 39 of 44