Process Analytics Sensor Maintenance

Process pH, chemistry, temperature, and pressure are just some of the factors that you need to think about when selecting a pH sensor for a particular application. If the wrong sensor’s selected, it could fail in a few weeks or even just days, which leads to regular sensor exchange and a costly measurement point.

On the other hand, the right sensor could measure reliably in the exact same process for a year or more.

pH sensors come in a variety of glass membranes, reference systems, and other features that help them cope with a wide range of measurement conditions.

To help reduce maintenance and keep running costs low, choose sensors that are fit for the tasks. 

Probably not.

Predicting when a sensor will need calibrated or replaced usually relies on a mix of experience and guesswork.

To simplify planning, most facilities run maintenance to a schedule. For example, you calibrate the sensor at a particular measurement point once a month and replace it every six months.

You hope this approach catches any sensor that’s about to fail and that you’re not doing maintenance too often when it’s not required.

An alternative approach is to use digital sensors.

Calibration means taking buffers, water for rinsing, etc., to the measurement point. This makes it cumbersome, and if the sensor and transmitter are not physically close to each other, a two-person team is required.

Not only that, calibration can take a lot of time. From start to finish, following all the steps can take up to an hour!

With such software programs, you only need to gather the necessary buffers, etc., then follow the software’s on-screen instructions.

If the technician misses a step or doesn’t do it fully, the software alerts them. Because such programs provide all the necessary instructions, training isn’t really required.  

Calibrating sensors away from the process and using calibration software doesn’t just make the whole process easier, it makes it much faster.

Another advantage these systems offer is that measurement points considered too costly to operate due to their need for frequent maintenance, now become economical to run.

As mentioned, these systems make use of retractable sensor housings.

These housings offer a further benefit that helps to reduce sensor maintenance. Many processes may not need a continuous measurement. Perhaps one measurement every hour is sufficient. In such cases, the sensor can be kept safe in the housing and only inserted into the process when a measurement’s required.

This significantly increases sensor lifetime and dramatically reduces maintenance and the frequency of replacement, as well as reducing costs.