K-Patents PR-23 Troubleshooting Guide - Manual (Page 8)

TROUBLESHOOTING GUIDE
FOR PR-23 ALL MODELS 8 (14)
January 9, 2015
K-PATENTS OY

Postal Address: P.O.Box 77, FI-01511 Vantaa, Finland

Street Address: Elannontie 5, FI-01510 Vantaa, Finland

Tel. int.+358 207 291 570
Fax int.+358 207 291 577  [email protected]  www.kpatents.com  Vat No. FI03035575  Business ID 0303557-5  Registered in Helsinki
HD TEMP = High temperatures can damage the electric components. Prolonged high temperatures inside
the sensor may result in short circuits on the electric boards and component failures.
HD HUM = High humidity inside the sensor is harmful to the electric components. High humidity could also
indicate leakages, but it is common that the humidity starts to increase inside the instrument after the dryer
have saturated over time. Generally, high humidity can be resolved by changing the dryer, which is also
recommended every time the sensor cover is opened.
3. Prism wash
Prism wash is the most important and sensitive part of the whole measurement system. If the wash is not
sufficient the prism will get coated, which will cause drifting and spiking outputs. However, too aggressive
wash is the most common reason for refractometer failure, as it leads to the prism erosion. The same
principle applies in both steam and high pressure water wash. Therefore it is critical to understand the
importance of the washing parameters.
The transmitter can be used to control the wash cycle. The wash parameters can be configured by pressing
MENU  5 CALIBRATION  4 PRISM WASH. The most important wash parameters are listed and
explained below.
Preconditioning time: This function activates “Preconditioning relay” always at the beginning of the washing
cycle. It is used to clear condensate from the steam pipes before actual prism wash.
Figure 7
Automatic prism wash cycle
Wash time: Determines the time the wash valve is open. Typical washing times are 3-5 seconds with steam
and 5-15 seconds with water. Longer wash times will decrease the life time of the prism.
Recover time: The mA-output is normally on hold during wash to prevent unnecessary disturbances in the
signal to the DCS. The recovery time determines the duration of mA-output hold after the actual wash.
Preset value is 20 seconds.
Wash interval: The time between two wash cycles. It is recommended to shorten the wash interval than
increase wash time, if there are problems with prism coating. Preset values is 20 minutes.
Empty pipe check: This function prevents unnecessary washing during stoppages, when the pipes are