Smartreader Plus 2 Temperature & Relative Humidity Logger; Description; Setup - ACR Electronics SmartReader Plus Reference Manual

1.4
SmartReader Plus 2 Temperature & Relative Humidity Logger
A self-contained "air-quality" logger, the SmartReader Plus 2 can be used easily in a wide
variety of applications to collect temperature and relative humidity data.
1.4.1

Description

The SmartReader Plus 2 includes an on-board thermistor temperature sensor and a plug-in
RH Sensor plus two input channels for an optional remote temperature and relative humidity
probe.
How It Works
The relative humidity sensor in the SmartReader Plus 2 is a processed plastic wafer. This
wafer is actually a laser-trimmed, capacitive thin-film relative humidity sensor.
Changes in relative humidity cause the surface capacitance of the polymer film to vary. The
SmartReader Plus 2 gauges this capacitance by passing a small electric current through it and
measuring the relative voltage drop. Because the response of the sensor is temperature
dependent, a temperature reading is always taken at the same time as the humidity reading.
That way, when the logger's information is backed up into your computer, TrendReader
software can automatically factor in the right compensation values when it calculates the
percentage of Relative Humidity (in % RH). The result is an accurate set of
automatically-generated and temperature-compensated relative humidity readings.
1.4.2

Setup

Make sure to enable each channel you want to use. If you are not using a channel, disable it
in order to save memory.
Copyright © 2010 ACR Systems Inc. All Rights Reserved.
Figure 2-1: SmartReader Plus 2
Channel
SmartReader Plus Data Logger
Description
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