NO. INDICATION
LIKELY REASON
SOLUTION
9
The error between
DPM mass flow
reading and
another meter
connected in
series is more
than combined
accuracy for both
instruments.
1. Instruments may be
configured to measure
different Gas.
1. Check that both instruments
are configured to measure the
same Gas.
2. Other meter mass flow
may have different standard
conditions settings.
2. Make sure both instruments
provide mass flow reading for
the same Standard Conditions.
3. There is leakage in the
pipe between the DPM and
other meter.
3. Check installation
connections for leakage.
10
Gas flows through
the DPM, output
voltage 0-5Vdc
signal does not
respond to flow
(reading near
1mV). OLED
Display reading is
negative.
Direction of the gas flow is
reversed.
Check the direction of gas flow
as indicated by the arrow on
the front of the meter and
make required reconnection in
the installation.
DPM is connected in the
installation with back
pressure conditions, and a
gas leak exists in the
system.
Locate and correct gas leak in
the system. If DPM has internal
leak, return it to factory for
repair.
11
Flow reading is
unstable or jumps
up and down.
1. The DPM instrument
response time is less than
20 ms, which makes meter
react on quick flow
variations normally
associated with diaphragm
pumps or faulty pressure
regulators.
1. DPM has Signal Conditioner
settings which allow user to
adjust instrument response
time constant according to
application requirements.
2. Some obstructions
(Teflon tape shreds or other
big particulars) in the
upstream connection.
2. Inspect inside of instrument
upstream connections for
debris.
12
The Diagnostic
event code 0 is
active
CPU temperature is too high
(overload).
Disconnect power from the
DPM. Make sure the ambient
temperature is within specified
range (below 60°C). Let the
device cool down for at least
15 minutes. Apply power to the
DPM and check DE #0 status.
If DE with code #0 is active
again, the unit has to be
returned to the factory for
repair.
13
The Status LED
indicator is
constantly on with
the RED light.
Fatal Error (EEPROM or
Auto Zero error).
Cycle the power on the DPM. If
Status LED still constantly on
with RED light, wait 1 minute
and start Auto Zero function
(see Section
6.4.
4 Zero Calibration). If
after Zero Calibration the Fatal
Error condition appears again,
return the meter to the factory
for repair.
