OdaLog
®
Gas Logger User Manual
P/N: 10-1000
Revision: F, Issued: October 2019
Page: 18
7.2.2 Humidity
The sensors fitted to the OdaLog
®
Logger can be used continuously in atmospheres of 20% to 80% relative
humidity (RH), and can be used intermittently between 0 to 20% and 80 to 99% RH. If used for extended
periods of time at low humidity, the sensor may dry out. Conversely at high humidity it may take up water
and leak acid.
In high RH environments (over 90%), a time-in / time-out ratio of two days “in” and two days “out” is
recommended. This allows the sensor adequate time in a ‘normal air’ environment to ‘dry out’ and return to
its normal operational state.
Under these conditions, regular physical checks and calibration of the sensor is essential and an after use
“span check” is recommended for such environments (See Section 9.8).
7.2.3 Pressure
Sensors may exhibit effects to changes in pressure. For example, an increase in pressure may result in an
increase in gas reading. For this reason, we do not recommend this sensor for use in pressurised
applications.
7.3 Long Term Exposure to High Gas Levels
It is possible for some electrochemical sensors to “drop off” in reading when exposed to high levels of gas
for extended periods. Therefore, a “pre-use” and “post-use” span check may need to be carried out as
described in Section 9.8.
IMPORTANT NOTE ON HUMIDITY:
The Sensor fitted to the OdaLog Instrument is susceptible to reduced response
in continuous high-humidity environments. With the wastewater industry being
a common application for the OdaLog, it is IMPORTANT that users understand
the effect humidity has on the sensor. The OdaLog and that it can not operate
continuously in a ‘wet’ (above 80% RH) environment without an ongoing
operating and service plan to ensure the accuracy of logged data.