Vaisala PR-23 Series - Setting Prism Wash Parameters

7.5.2 Setting prism wash parameters
To set the prism wash parameters for a given sensor, fir
st select the sensor, then select 5
CALIBRATION from the Main menu, and then 4 PRISM WASH. This menu contains the
alternatives (factory settings are given in parentheses):
Parameter Value
1 PRECONDITION TIME 0 … 30 s (0 s)
2 WASH TIME 0 … 30 s (3 s)
3 RECOVERY TIME 0 … 30 s (20 s)
4 WASH INTERVAL 0 … 1440 min (20 min)
5 WASH CHECK MODE (Disabled)
6 HOLD DURING WASH (Active)
7 TEMP LIMIT ACTIVATION
8 TEMP LIMIT VALUE °C
9 EMPTY PIPE CHECK (Active)
0 MORE...
1 WASH nD LIMIT
2 WASH TOLERANCE TIME (0 min)
The prism wash cycle:
See Figure 43 (page 81) and Wash cycle (page 77). The timing of the
wash cycle is controlled by the WASH INTERVAL, PRECONDITION TIME, WASH TIME and
RECOVERY TIME settings. If the WASH INTERVAL is set to zero, the wash can be initiated
only by using the manual wash or remote wash request.
If the
PRECONDITION TIME is zero (or there is no relay configured for preconditioning), the
preconditioning phase is skipped. If the WASH TIME is zero (or there is no relay for wash),
the wash functionality is completely disabled.
Wash check: The prism wash check monitors automatically that the wash really has an
eect on the prism. In the
WASH CHECK STANDARD mode, prism wash is accepted if the
refractive index n
D
either falls below wash n
D
limit (default 1.34) at Normal operation or NO
SAMPLE occurs. This is the indication of a successful wash with water or steam.
If the wash is not accepted, the diagnostic message PRISM WASH WARNING, see Diagnostic
message priorities (page 97)
, displays. If no wash is accepted during wash tolerance time,
the message becomes PRISM WASH FAILURE. Both messages and the wash tolerance
counter are reset by a successful wash.
The
WASH CHECK AUTOMATIC WASH CUT mode diers from the standard mode by
stopping the wash 2 s after the n
D
falls below the limit.
To stop the measurement for the duration of the prism wash, choose 6 HOLD DURING
WASH and in that menu activate the hold function. The CONC reading and mA outputare
held in the value they had immediately before starting the wash cycle.
PR-23 Series User Guide
IM-EN-PR23-E
82