Endress+Hauser Topcal S CPC310, Руководство по эксплуатации

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Maintenance
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Reduced reference system
The inner metal lead of the reference system (Ag/AgCl) of a combination electrode or a separate
reference electrode is usually light-brown and matt. A silver-colored reference system is reduced
and therefore defective. The cause is a current flowing through the reference element. Possible cau-
ses:
• Incorrect operating mode selected for the measuring device (PM pin connected but
unsymmetrical operating mode selected ("no solutiong ground"). See the function description on
"Selecting the type of connection".
• Shunt in measuring cable (e.g. due to humidity) between reference line and grounded screen or
PA line.
• Measuring instrument defective (shunt in reference input or entire input amplifier downstream
of PE).
8.1.3 Maintenance of digital sensors
Please proceed as follows to maintain digital sensors with Memosens functionality:
1. If an error occurs or the sensor has to be replaced as per the maintenance diagram, take a new
or precalibrated sensor from the lab.
A sensor is calibrated in the lab under optimum external conditions to ensure a higher quality
of measurement.
2. Remove the fouled sensor and install the new one.
3. Calibration is necessary if you use a sensor that has not been precalibrated.
4. The sensor data are automatically taken from the transmitter. No release code is necessary.
5. Measuring continues.
6. Take the used sensor back to the lab. You can prepare the sensor for reuse in the lab without
causing measuring point downtime.
– Clean the sensor. For this purpose, use the cleaning agents specified for the sensor.
– Inspect the sensor for cracks or other damage.
– If no damage is present, regenerate the sensor. For this purpose, store the sensor in 3M KCl
solution for 24 hours.
– Recalibrate the sensor for reuse.
8.1.4 Liquid KCl supply
• KCl must be bubble-free. In the unpressurized version, check whether the cotton thread is in the
hose.
• In the event of counterpressure: Check whether the pressure in the KCl tank is min. 0.8 bar
(12 psi) above the medium pressure.
• The consumption of KCl should be low but noticeable. Approx. 1 ... 10 ml/day is a typical value.
• In the case of sensors with a KCl refill opening on the glass shaft, this opening must be free and
unobstructed.
8.1.5 Manual calibration
The calibration of the sensor is an integral part of the Topcal S system. An additional or external
calibration of the sensor is thus not necessary.
If you are using analog sensors and want to perform a calibration outside the assembly (e.g. for test
purposes), observe the operating mode of the pH input. In the "solution ground" (=symmetrical
connection) operating mode, the PM line of CPM153 must be immersed in the calibration solution.
!
Note!
The assembly must be moved to the Service position with the service switch before manual
calibration can be performed.