Products for USB Sensing and Control
Products for USB Sensing and Control


Unit 1 - 6115 4 St SE
Calgary AB  T2H 2H9
+1 403 282-7335

PC2121-5M pH Industrial Electrode

ID: 3551_0
Recommended for new designs: Phidgets Inc. is not the original manufacturer for this product, but we intend to sell it (or a similar replacement with a compatible form, fit and function) for as long as it is available from the supplier.

This industrial electrode measures the pH of a solution and connects to a pH/ORP Adapter.


Quantity Available: 42

Qty Price
5 $96.00
10 $92.00

The 3551 is an economical combination electrode ideal for general industrial processes. It is well suited for testing pool water, sea water or underground water. It can also be used at high temperature in strong acid or base environments.

The electrode provides a fast, stable response and is ideal for prolonged pH readings. The sealed, high polymer gel-filled design requires virtually no maintenance as there is no need to refill the reference chamber.

The outer tube is made of strong PPS plastic and is threaded (3/4" NPT pipe thread) for ease of installation.

The 3551 measures 160 mm (length) x 29 mm (diameter), can withstand temperatures up to 110°C and measures pH levels from 0 to 14.

It comes with a 6 meter cable terminated by a BNC connector and a bottle of pH electrode solution.

Comes Packaged with

  • A small bottle of buffer solution

When you receive this sensor, fill the cap with buffer solution and ensure that it has no leaks.


This probe connects to the BNC connector on our pH interface boards. See the Connection & Compatibility tab for a complete list of options.

pH/ORP Interfaces

This pH electrode creates a voltage differential that can be read by one of our pH/ORP interfaces:

Product Sensor Properties
Image Part Number Price Controlled By
1130_0B $30.00 Voltage Input (0-5V)
ADP1000_0 $25.00 VINT

Product Specifications

Electrode Properties
Electrode Type Combination Single-Junction (pH)
pH Measurement Range 0 to 14
Electrode Response Time Max 10 s
Operating Temperature Min 0 °C
Operating Temperature Max 110 °C
Physical Properties
Exterior Tube Material PPS Plastic
Maximum Pressure 87 psi
Connector Type BNC
Rear Thread Type 3/4" Pipe Thread
Length 160 mm
Diameter 29.3 mm
Cable Length 5 m
Customs Information
Canadian HS Export Code 9027.89.00
American HTS Import Code 9027.89.45.30
Country of Origin CN (China)


Here is a complete list of the water quality probes we carry:

Product Electrode Properties Physical Properties
Image Part Number Price Electrode Type Operating Temperature Max Exterior Tube Material
3550_0 $25.00 Combination Single-Junction (pH) 80 °C Impact Resistant Plastic
3551_0 $100.00 Combination Single-Junction (pH) 110 °C PPS Plastic
3555_0 $70.00 Combination Single-Junction (ORP) 80 °C Impact Resistant Plastic
3556_0 $110.00 Combination Single-Junction (ORP) 110 °C PPS Plastic