PST Michell Instruments S8000 -100, User Manual, Page: 25 / 68

S8000 -100 User Manual
Michell Instruments 17
OPERATION
3.3.1.2 Operating Practice
Avoid situations in your operating cycle where a dew point is introduced to the
instrument which is greater than the current sensor temperature. Precautions should be
taken to either gradually increase the sample humidity, or manually change the cooler
temperature in advance. If precautions are not taken, condensation may form in the
inlet tubing – see Section 3.3.1.3, Flood Recovery, for more detail.
Purge Times
When measuring very dry frost points, the instrument needs to be adequately purged
with the sample while the sensor is in standby mode. If a measurement is attempted
before the instrument internal sample path and associated inlet tubing are close to
equilibrium, then a poor frost formation may result. Recommended purge times are as
follows:
Frost Point (°C) Time (hours)
-80 12
-90 24
-100 48
3.3.1.3 Flood Recovery
If the sensor has detected that a flooding event has occurred, the following steps will
be taken to recover the measurement:
1. The sensor cooler will be switched off, and the sensor temperature will rise to
+20 °C (+68 °F).
2. The mirror temperature will be increased.
3. Once the sensor temperature has r20 °C (+68 °F), a DCC will be initiated.
4. Once a DCC cycle has been completed, normal measurement will resume.
The instrument will indicate when flood recovery is active by displaying
Flood
as the
Mode in the Operational Status Display.