VEGA D98 Pressure transmitter - Manual (Page 10)

10 Pressure transmitter D98
Diagnostics
5 Diagnostics
Maintenance
When properly used, pressure transmitters
D98 are maintenance-free.
Should a dismounting of the pressure trans-
mitter be necessary (e.g. vessel cleaning)
we recommend the use of a new seal. You
should only use VEGA seals.
Troubleshooting
If faults do occur, the following measures
must be taken before dismounting the
pressure transmitter:
- check the atmospheric pressure compen-
sation (only with gauge measuring ranges)
- check the electrical connections.
Check the atmospheric pressure compen-
sation
Open the cover of the housing. The meas-
ured value must not change. However, if the
displayed value changes, compensation of
the atmospheric pressure is not ensured,
which can result in distortion of the measured
value. Make sure the breather unit is unob-
structed. It consists of a black plastic
threaded insert with integrated filter element.
Note:
The pressure acting on the breather must be
the same as the atmospheric pressure in the
open vessel.
Terminals
Pressure
transmitter
~
1 2 3
+
–
voltage current
current
external
energy
V mA
mA
transmitter must be at least 12 V DC.
Check the voltage
- The terminal voltage on the pressure
Check the current
• Initial current with unimmersed diaphragm
of pressure transmitter: approx. 4 mA
• operating measuring current: 4 … 20 mA
• Exceeding or falling short of the specified
measuring range: 20.5 mA and 3.8 mA
• Pressure transmitter damaged or short-
circuited: current > 22 mA or < 3.6 mA
Check the electrical connections