EXO Maintenance - pH Module

EXO Maintenance - pH Module

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EXO Maintenance - pH Module

This video covers the installation and maintenance of the EXO pH sensor module.

Timestamps of specific moments of the video

  • 0:00 – Overview
  • 0:25 – Removing the old pH Module
  • 1:23 – Cleaning the Sensor
  • 1:41 – Installing the new pH Module
  • 2:45 – Sensor Storage

Video Transcript

In this video, we'll be replacing the EXO pH sensor module.

EXO pH and pH/ORP sensors feature convenient, replaceable modules, so you don’t have to worry about dealing with a refill solution. These modules typically last over 12 months, depending on use conditions, and they have a 1-year warranty!

To start, let’s remove the pH sensor from the EXO Sonde. To do this, I’m going to tilt the sonde down a little to ensure that no water droplets enter the port. Next, we are going to remove and discard the old sticker from the sensor. With the sticker removed, you will see that there is a rubber plug positioned in the plastic ring at the base of the sensor module; this keeps the locking mechanism in place. We’ll remove this plug with a flat-head screwdriver.

With the plug removed, we can now squeeze the plastic ring so that it compresses the gap left by the plug. Next, we’ll pull the sensor module straight back from the sensor body. You may need to wiggle it slightly to get it out and it may require a little bit of effort.

Note that the act of removing the module damages its o-rings, so do not try to reuse the old o-rings. Once the old module is removed, inspect the port for any debris. You can use a Kimwipe to clean the port of any old o-ring grease. And you can use compressed air to remove any moisture if present.

Next, we’ll take our new sensor module and check the o-rings to make sure they are seated correctly and not damaged. We also want to make sure that they are lubricated prior to installation. New modules should already be lubricated, but it is always good to check. Additionally, avoid using too much grease, as that might compromise the seal.

The sensor module is keyed to fit in only one orientation. Make sure to line up the prongs with the gaps inside the port. You’ll notice a small one and a large one. With the sensor lined up, firmly press until the module clicks into place. Wipe away any excess o-ring grease that may be present on the sensor. Every new module includes a sticker where you can write the install date with a permanent marker. We’ll wrap the seam where the module meets the sensor with this sticker. And with that, our new pH sensor module is installed.

For short-term storage, you can keep the sensor in a humid air environment, such as a sealed EXO cal cup with a small amount of tap water. For long-term storage, the sensor tip should be submerged in its original storage solution. A pH four buffer may be used as an alternative storage solution. Never store the pH sensor in distilled or deionized water, as this will rapidly deplete the reference gel and shorten the life of the module.

After the new module is installed, it is necessary to perform a calibration before use. Please be sure to check out our other EXO University videos. Thanks for watching!

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Related Videos

ORP Sensor Calibration

Sonde Storage