K-Patents PR-03 User Manual

Page 46

PR-03 instruction manual

5.9.1 Timed wash

When an external relay unit is used as a wash timer, the time settings are entered after the sequence Cali-
brate / Parameters / Prism wash

− Preconditioning time s (0)
− Wash time, s (3)
− Recovery time, s (30)
− Wash interval, min (20)

The default values for timed wash are given in parenthesis. The output signal is locked during wash and
recovery time.

WASH

RECOVERY

INTERVAL

PRECOND.

Figure 5.12

Prism wash sequence

Note:

The wash interval timer starts a wash at a preset interval after last wash, independently of how the

last wash was initiated. If the wash interval is set to zero, the timer will not initiate a wash.

Wash type

Time

Pressure

Recovery

Interval

Steam wash

3-5 sec.

5-6 bar (73-87 psi)

20-30 s

20-30 min

High pressure water wash

10-15 sec.

20-30 bar (290-435 psi)

20-30 s

10-20 min

Table 5.1

Recommended prism wash times for the PR-03 sensors

Important:

In steam wash, do not exceed the recommended wash times, because some process media may

burn to the prism surface if steamed for longer time. In case of coating, shorten the wash interval.

5.9.2 Smart wash

Sometimes it is necessary to modify the standard wash routine to fit the application better. The Smart wash
feature allows you define better when wash is needed and when it should not be implemented.

The Smart wash starts the wash when the prism shows signs of being coated. An early indicator of beginning
coating is that the Slope decreases. Slope is a measure of the sharpness of the optical image (Section 5.5.4).

The Smart wash settings are made at Calibrate / Parameters / Prism Wash / Smart
wash

Slope limit

A wash is initiated when the Slope value goes below this limit. The Slope limit has to
be set based on observations of slope values both at clean prism and at slight coating.
When the slope limit is set to zero, this Smart wash function is inactive.