DIFFERENTIAL SENSORS

In this type of sensor, the silver/silver chloride reference element has been replaced by a pH sensitive glass electrode identical to the measuring electrode. This second glass electrode is housed in a chamber filled with pH 7 buffer which provides a stable reference. A high surface area reference junction electrically connects this reference system to the pH measuring element. The result is that pH is measured by the voltage difference between the two pH sensitive glass elements.
Differential pH sensors are the best choice for demanding applications such as wastewater, plating baths, aggressive industrial process water, or higher temperature applications. They are especially good in applications containing sulfur compounds that tend to poison the silver/silver chloride reference element found in conventional sensors. Because they are designed with replaceable reference junctions and have internal preamplifiers, these sensors tend to significantly outlast conventional sensors.
PRODUCT FEATURES
Sensor Options
Choice of either “differential” or “conventional” pH sensors. Differential sensors provide reliable, long lasting service in demanding applications while conventional sensors provide a lower cost alternative for clean water applications.
Auto-Cleaning
Automatic “Air Blast” sensor cleaning system available for reducing maintenance in applications where sensor fouling is a problem.
Calibration
Automatic buffer recognition simplifies calibration.
AC or DC Power Options
Power options include universal 100-240 VAC or 12-24 VDC.
Analog Output Options
Two isolated 4-20 mA outputs are standard, with an option for a third output if required. Default setting provides analog outputs for pH/ORP and temperature.
PID Output
Standard PID control function assignable to one analog output.<
Digital Communications
Available for either Profibus-DP, Modbus-RTU, or Ethernet-IP.
Relay Contacts
Three SPDT relays are standard, with relay functions programmable for alarm, control, or trouble indication. Three additional low power relays available as an option.
Flexible Mounting
NEMA 4X (IP-66) enclosure is suitable for wall, pipe, or panel mounting.
Clear Display
Back-lit large LCD display provides clear visibility in any lighting conditions. A scrolling second line on the display provides additional information and programming prompts.