pH Sensor Offers Increased Stability

March 23, 2009
Emerson unveils the PUR-Sense Model 3800 pH sensor

Emerson Process Management has unveiled an autoclavable and steam-sterilizable pH sensor designed for stability in life science applications. The Rosemount Analytical PUR-Sense 3800 offers sensor stability that is up to five times greater than any other pH sensor previously available.

In simulated cell-culture processes, the PUR-Sense 3800 exhibited sensor drifts below 0.1 pH after an autoclave of 125°C for 45 minutes. Additional testing showed continued sensor life after more than 30 autoclave cycles or 50 steam cycles.

The reliability and stability of the PUR-Sense 3800 in high heat environments is based upon the Emerson PERpH-X and AccuGlass technologies. High temperatures can cause pH glass sensing membranes to deteriorate. The AccuGlass pH bulb addresses this issue and resists cracking and aging while exhibiting near theoretical responses, even at extreme pH values. The PUR-Sense reference electrode uses a silver-silver chloride-based reference electrode in combination with a gelled potassium chloride electrolyte to provide a stable reference potential through the single proprietary ceramic reference junction.

The PUR-Sense Model 3800 provides an individual quality certification with calibration records and a list of wetted materials for each sensor. The sensor is available in three different insertion lengths: 120 millimeters, 225 millimeters and 325 millimeters. The 3800VP has a PT100 ohm RTD mounted inside the pH glass stem for automatic temperature compensation.