Genral Water Catalogue - Crison Instruments - #9

These are specific instruments for measuring and, in some cases, controlling pH and mV in conti­nuous processes.

There are different versions depen­ding on the requirements for appli­cation and location. The following versions are avai­lable:

• field and panel,

• with different voltages, 230, 115 or 24V A/C

• transmitters or controllers

• different regulation modes: on/off or proportional

• etc.

pH and temperature values are displayed simultaneously. The display is backlit, which aids reading in dark places. During calibration, the instruments automatically recognize buffers and have built-in criteria for acce­pting/rejecting the electrode. The instruments are compatible with most glass-membrane pH electrodes on the market. These instruments are very easy to handle.

They enable interactive dialogue in the user's own language (Spanish, English, French and Italian). The display always provides the user with instructions for opera­tion or help messages. An access code prevents unautho­rised personnel from interrupting measurement processes. Only authorised personnel can calibrate or program the equipment. During calibration and program­ming, the instrument remains on hold.

The field versions have a water­tight transparent cover to protect the keypad and display. The panel versions are especially prepared for mounting on standar­dised panels.

PH27 P

Active pH/mV transmitter (4-wire) Analogue signal from 4...20 mA, user-programmable, to be built into automated processes. See fig. on page 9.

Only available in panel version, 96x96. PH 28

pH/mV Controller. Available in field and panel versions. Apart from an analogue 4...20 mA output, it has two relays, both of which can be programmed to act either as maximum or minimum. Performs on/off regulation.

PH 29

pH/mV controller. Available in field and panel versions.

The features which distinguish it from the PH 27 and the PH 28 are:

• 3 relays: 1 for limit, 1 for alarm and the third can be used as a limit or electrode cleaning.

• Proportional regulation, as well as on/off.

• As well as classic calibration with buffers, it allows the user to perform indirect calibration.

• Data logger. Stores up to 200 measurements. The data can be memorised with a scheduled frequency or, for example, when measurements are outside limits.

• Possibility of verifying installation; relays activation and 4...20 mA output.

All models are supplied with the EC Declaration of Conformity as per EMC directives 73/23/EC on low-voltage devices and 89/336/EC, and with specifications certificate.