User manual

User Manual
5
5. General Description
The HC2S3 is a digital probe with 0 to 1 V linear output signals for temperature
and humidity, and a UART serial interface. The voltage signals can be
measured with two single-ended or two differential inputs on the datalogger. A
special Rotronic cable and the SDM-SIO1 Serial I/O Module or MD485 RS-485
Interface is required to interface with the UART as described in Appendix B.
The D/A converter used to generate the analogue output signals has 16-bit
resolution. The default configuration is for temperature -40° to +60°C, and
0 - 100% relative humidity. Temperature range and other default settings can be
changed as described in Appendix A.
A cable ordered through CSI for the HC2S3 includes an internal voltage
regulator that applies 3.3 V to the probe from a 5 to 24 V power source. 12V
power is recommended for use with CSI dataloggers. Where minimizing power
use is important, power can be switched on and off for the measurement
provided there is a 3-second warm-up delay. Switching power avoids the
constant current flow through datalogger ground, which can affect the accuracy
of low level single-ended voltage measurements, primarily with older
dataloggers such as the 21X.
Probes are polarity protected by the keyed connector and a diode in the
connector interface provided with the CSI cable.
CSI offers two filters:
Polyethylene filter: Default filter, protection against fine dust particles,
no water absorption or retention, good response time.
Teflon filter: Recommended for marine environments, slower response
time than the polyethylene filter, ordered separately.
6. Specifications
Operating Limits at Electronics: -40°C to +100°C
Storage Temperature: -50°C to +100°C
Probe Length: 85 mm (3.3 "), 121 mm (4.75”) including connector
Probe Diameter: 15 mm (0.6 ")
Probe Weight: 10 g (0.35 oz)
Filter: Polyethylene or Teflon (optional, ordered separately)
Power Consumption: <4.3 mA @ 5 V
<2.0 mA @ 12 V
Supply Voltage (using CSI cable): 5 to 24 VDC (12 VDC recommended)
Start-up time: 1.5 sec typical (Rotronic specification, CSI recommends 2 sec at
60°C, 3 sec at 0°C, 4 sec at -40°C)
Maximum Startup Current: <50 mA during 2 µs
Maximum Lead Length: 300 m (1000') with 12 V power, 3 m (10') with 5 V
power
Analogue outputs:
Offset at 0 V: ±3 mV (maximum)
Deviation for Digital Signal: < ±1 mV (0.1°C, 0.1% RH)