Cerlic pHX, Руководство пользователя, Страница: 3 / 24

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1. Introduction
pHX / ReX are used to measure pH or Redox potential in water and wastewater
treatment plants and other industrial applications.
2. A few words about this manual
This manual details installation procedures and operational features of the Cerlic pH and
Redox sensors. Menu navigation and technical data for the BB2 control box can be
found in the BB2 service manual .
3. Design
The pHX / ReX sensors are manufactured in SIS2343 (316SS) stainless steel and PVC.
The sensors are mounted using PVC clamps. An adjustable stainless steel slide rail
holder is available as an option as well as equipment for automatic cleaning.
The sensor has a fixed, shielded 10 m (33’) cable used for signal transmission between
the sensor and the BB2 control box.
4. Measuring principle
pH is normally measured with an electrode where pH is expressed as a function of
voltage. Today's electrodes often contain both a measuring electrode and a reference
electrode, which in combination provide a voltage in linear proportion to the pH value.
Electrodes internally combined with a reference and measuring cell are divided into two
categories: gel electrodes and refillable electrodes. The gel electrode is the simpler and
less expensive type. There are a number of different types of refillable electrodes for
different applications, each with different internal solutions that are to be added at
regular intervals. Cerlic provides a gel-filled glass electrode.
The temperature of the calibration buffer and the media to be measured can be entered
in BB2 to compensate for the temperature dependence of the electrode. All settings are
made in the central unit BB2 using a self-instructing menu controlled by just three keys.
The output signal is frozen when you switch to menu mode so that the output signal will
not change during procedures such a re-calibration.
The BB2 has two 4-20 mA outputs, and relay outputs for alarm and cleaning of the
electrode.
The current pH/mV is continuously displayed in a window, maximum, minimum and
average values for the last 24 hours can be obtained by pressing two buttons.