Tomtech - Model PHM2 -PH Monitor Sensors

The PHM2 pH monitor is a rugged unit designed to provide signal conditioning and calibration for a pH electrode. It has analogue pH signal and relay outputs. The monitor is housed in a waterproof polycarbonate enclosure with clear hinged lid which with the lid closed meets the requirements of IP54. The pH input is fully isolated from the outputs for reliable pH measurement eliminating problems with interaction with other equipment. High and low thresholds may be set to operate the output relay which may be used as an alarm or for control purposes. All electrical connections are via screw terminals, the electrode connects via a BNC plug. The pH monitor has the following facilities:
pH Display: A clear liquid crystal display shows pH over the range 4 to 9 pH with a resolution of 0.01 pH units. The display can be easily read with the front cover closed.

• pH Electrode Input: The input will connect to any standard pH combination electrode fitted with a BNC plug. The electrode is fully electrically isolated from the pH outputs to 1Kvolt.
• Electrode Calibration: Two point calibration with front panel adjustments allowing the buffer offset at 7pH and slope at 4pH to be adjusted.
• Alarm Thresholds: High and low thresholds may be independently set. These are accessed by pressing the SET push button, the display shows the threshold which may then be adjusted.
• Alarm outputs: If the current alarm threshold is exceeded this will activate a two pole relay with volt free normally open, common and normally closed contacts, front panel red LED and display warning message. All relay connections are available on terminals.
• Signal outputs: Two outputs are available; 4-20 mA and 0-5v corresponding to the 4 to 9 pH range.

• Overall Dimensions: 220mm. width, 230mm. height,126mm. depth
• Electrical supply: 120 or 240 volts AC 6VA
• Analogue output: 4-20mA and 0-5 volt corresponding to 4-9pH
• Relay output: 2 pole changeover rated 5A at 240 volt AC