HEASTERN Industries has announced a new unique head-mounting loop-powered (4-20 mA output) transmitter for pH electrodes with precise temperature compensation. The design (hockey puck style) will allow direct mounting into a standard IP65 (thermocouple style) head assembly.
All pH electrodes, being high impedance devices, produce a millivolt (mV) output signal, proportional to the measured pH. This signal (mV) is not ideal for many applications (such as process control on effluent run offmonitoring, etc.), where the pH sensor is mounted quite some distance from the final monitoring/control instruments.
The Model IQ-2262 solves this problem.
The "raw" pH signal is processed, at the point of measurement, into a "standardised" 4-20mA process signal. This 4-20mA "pH proportional" signal can then be transmitted over long distances (with additional advantage of no compromise of calibration).
Only two wires are required between the point of pH measurement (in the field) and the receiving instrument, and they are immune to interference from adjacent voltage-carrying cables.
The IQ-2262 in-head pH transmitter can be used with any brand of combination style pH pipeline electrode. A PT1000 integral temperature sensor (in the pH electrode) allows for precise temperature compensation.
Local "standardise" and "slope" adjustments are incorporated for field calibration set-ups. A local LED indicator shows correct functioning of the unit. Reverse polarity (supply) protection is also provided.
The IQ-2262 offers a robust, effective and economic solution to many pH measurement applications.