Easidew DryCheck User’s Manual
Michell Instruments
9
OPERATION
3.2
Preparation For Operation
3.2.1 First Time Operation
To commence operation, proceed as follows:
1. Check that electrical power supply and the relevant analog and alarm
outputs are connected to external systems as required and as described
in Section 2.8.
2.
Check that the gas sample flow rate through the sample block, or the
pipeline in which the transmitter is located, is within the operational
limits. (Adjust any external flow control valves, located in the gas sample
input line to the instrument to achieve required flow rate.)
3.
Switch on the power supply to the instrument. The instrument display
will now come on, typically showing the default parameters and units as
detailed in
Figure 7.
The instrument is now operational and after a few seconds, in which all the segments of
the display are tested, the monitor will display the measured dew-point temperature as
a steady reading within the range -100 to +20°Cdp (-148 to +68°Fdp), -60 to +60°Cdp
(-76 to 140°Fdp) / -50 to +50°Cdp (-58 to 122°Fdp) or 0 to 3000 ppm
V
depending upon
how the instrument has been set-up. The default setting is °C.
In the absence of any error indications the instrument will now be operational using the
default parameters.
Easidew Hygrometer
Figure 7
Typical Display
If the display is flashing, a fault condition exists. The following operational error
conditions may be encountered:
ErrL
- If the display is alternately flashing (e.g.)
ErrL
and
-103.3
, this
indicates that the measured dew point is outside the lower operational limit
(-100°Cdp/-148°Fdp).
If the display is alternately flashing
ErrL
and
-129.9
(
-199.9
if set-up to read
temperature in °F), this could be an indication that the input current loop to
the monitor is open or that there may be a transmitter fault. Check that the
transmitter is wired correctly as detailed in Section 2.8.
ErrH -
If the display is alternately flashing (e.g.)
ErrH
and
021.4
, this
indicates that the measured dew point is outside the upper operational
limit (+20°Cdp/+68°Fdp).