Vaisala PR-23 Series User Manual

Problem Cause Corrective action
Message TEMP MEA
SUREMENT
FAULT
Indicates faulty temperature
element.
Replace the temperature element.
A dier
ence to
some other
process
temperature
measurement is
not a fault.
PR‑23 measures
the true
temperature of
the prism
surface.
Concentration drift during Normal
oper
ation
For drift upward, suspect prism coating, see Prism coating (page 37).
Otherwise check calibration, see Calibrating concentration measurement
(page 72), and sensor verification, see Sensor verification (page 242).
Table 11 Wash troubleshooting
Problem Cause Corrective action
Message EX
TERNAL HOLD The concentration measurement is on HOLD due to an external switch
closure. For explanation, see Configuring input switches (page 68).
Messages PRE
CONDITIONING,
WASH, RECOVERING
PRECONDITIONING: An optional
preconditioning relay is closed.
See Configuring prism wash
(page 77).
WASH: The internal wash relay is
closed.
Configuring prism w
ash (page 77).
RECOVERING: The concentration
measur
ement is on HOLD during a
preset time.
Message PRISM WASH WARNING No dip of n
D
value during prism wash. The accepted size of the dip is set
as the WASH CHECK function, see Configuring prism wash (page 77).
See also Testing prism wash (page 51).
Message PRISM W
ASH FAILURE No dip of n
D
value during any prism wash during wash tolerance time.
The wash tolerance time is set in wash parameters, see Setting prism
wash parameters (page 82). See also Testing prism wash (page 51).
Message EX
TERNAL WASH STOP Tells that wash action is prevented because an EXTERNAL WASH STOP
switch is closed, see Configuring input switches (page 68).
• NO SAMPLE indicates an empty pipe.
Message L
OW TEMP WASH STOP Tells that wash action is prevented
because of LOW TEMP: low
process temperature indicates
empty pipe.
To set the limit, see Configuring
prism wash (page 77).
Message NO S
AMPLE / WASH
STOP
Tells that wash action is prevented because of NO SAMPLE: the process
pipe is empty and the prism is clean.
PR-23 Series User Guide
IM-EN-PR23-E
96

Vaisala PR-23 Series Specifications

General

Brand	Vaisala
Model	PR-23 Series
Category	Measuring Instruments
Language	English