SADP_Operating_ Instructions_0114
12 Problem
Guide
PROBLEM
CAUSE
SOLUTION
ERRATIC READINGS
Static on Indicator
Moisten indicator face with 50/50 mixture of
detergent & water, or use proprietary anti-static
cleaner.
DO
NOT
POLISH
INDICATOR
FACE.
FULL SCALE READING
Wet gas
Stop gas supply & switch analyser off.
Short
Circuit
Sensor
Disconnect plug from sensor & if the indicator
Cable or Plug
still reads over full scale deflection. Cure the
short circuit in the cable or plug or replace.
Short Circuit Sensor
Disconnect the plug from the sensor & note the
indicator falls to 0 deflection. Apply approx 24V
DC to sensor terminals MOMENTARILY with
the sensor in a dry condition. Polarity is not
important, but the contact must be brief or the
sensor
may
be
damaged. If this fails to clear the
fault
the
sensor
must
be
replaced.
ZERO READING
Open Circuit on Cable Disconnect plug from sensor and connect centre
pin of plug to the outer connection. No reading
will
be
obtained.
Repair
cable.
Open Circuit on Sensor Test as for open circuit on cable, but note that
reading over FSD obtained. Check sensor
connection
or
replace
sensor.
Autocal
Wrongly
Set.
Readjust
to correct setting (i.e. carry out the
Autocal
procedure
as
on
page
4).
Instrument
Disconnect coaxial cable from instrument and
Unserviceable
connect short circuit across terminals and note
no reading even with Autocal control turned up.
Return
instrument
for
service.
WET READING
Leak in System or
Cure leak, or replace unsuitable pipe with
use of Unsuitable Pipe copper or stainless steel. Flexible connections
should be made with PTFE pipe. NEVER use
rubber or plastic pipe.
Comparison
with
Ensure
that samples are taken from same sample
Secondary
Standard
point.
Re-check Autocal setting. If problems still
Instrument
or
occurs
change
sensor.
Calibration Gas
