Why Is The Gel In The Probe Turning Brown?

Over time, the high temperatures of sterilization will discolor the gel in a FermProbe. This is often referred to as carmelization. It is normal, and in no way affects the performance of the electrode. This color change can also be used to approximate the age of the electrode.

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What’s Inside?

The gel in a FermProbe® is a non-toxic, USP grade, organic material. Other manufacturers may use different materials such as polyacrylamide. Please call us for more information or an MSDS.

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What is the transmitter measuring?

Polarographic DO sensors measure the partial pressure of Oxygen within the vessel. In order for the transmitter to convert the sensor’s current output to % saturation or ppm concentration, the transmitter must know the operating temperature and pressure of the sample media.

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Why should DO sensors be calibrated after sterilization?

Calibration: To optimize the readings, dissolved oxygen probes should be calibrated in the process media, after sterilization. This is due to several factors: Sterilization could alter the sensor output. The tension of the membrane against the cathode is an important factor in the sensor signal. The high temperatures of sterilization…

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What is the probe measuring?

OxyProbes measure the partial pressure of oxygen. The partial pressure of Oxygen is dependent on the mixture of the gases and the pressure inside the vessel. Uncompensated variations in pressure can be a significant source of error. When reading % saturation or ppm, the operating pressure of the vessel should…

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How should I install a DO Sensor?

A DO sensor must be at least 15° above horizontal to consistently function properly. DO NOT install DO sensors in a port perpendicular to the vessel wall. The liquid in the sensor contains small air bubbles. If not inclined slightly above horizontal, a bubble can adhere to the cathode where…

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