Our most recent post talked about the third tip to help you prevent making costly mistakes with your water quality monitoring sonde.
Here is a quick refresher on Tip #3:
- Make sure your equipment is receiving regular preventative maintenance to extend its operational lifespan.
- Be prepared with spare hardware (sonde, sensors, handhelds) ready to go in case of an emergency.
- Maintaining equipment is equally or more important than buying it in the first place. While it can be challenging to find money for these expenses, do your best to budget for spares, accessories, and consumables that keep your equipment in good working order.
Now, here's the fourth helpful tip.
“Common, Costly Mistake #4”
Improper Handling & Storage
Often times when sondes aren’t being used, it’s out of sight, out of mind. Throughout the monitoring season when the equipment is being used on a daily or weekly basis, people consciously take all the right steps to keep their equipment in good shape. But when the monitoring season or a big project ends, often times the sondes and sensors can be stored improperly during off seasons and that can lead to unexpected results when you are ready to start using them again.
Improper pH Probe Storage
The number one way to destroy a pH probe (or ISE probes in general) is to store it in DI water. This is a pretty common occurrence when we’re talking about problems that arise with long term storage. DI water is very prevalent in most lab settings and often times it’s even used as a part of the rinse step in some organizations’ calibration processes. So it is easy to make the mistake storing your probes in it.
The problem is that when exposed to DI water for long periods of time, the reference standard inside a pH probe will become diluted, as all the hydrogen ions slowly rush across the concentration gradient formed from the De-ionized water. What we’re left with over time is a pH probe that is less responsive and has a significantly reduced lifespan.
Another mistake with pH probes is they are allowed to dry out – either in storage, or out in the field. pH is still one of the few parameters that is still based on electrochemical technology, and that means the probes must continue to stay in a hydrated environment at all times. Without wet storage, the reference wick dries out and will create erratic readings or slow response once the probe is used again in the field.
Now for either of these two problems, the simple solution is to store pH (and other ISE) probes according to the directions in your operations manual. For short term storage, or anything under a few weeks between uses, a humid environment is perfectly fine. Just put a small amount of tap water into your calibration/storage cup and you’re good to go. But for long term storage, prevent any damage to the pH probe by storing it in the solution it is shipped in, or if that’s unavailable, pH 4 buffer. The logic behind this is that these buffers closely resemble the KCL solution that is inside the probe.
Storage with Batteries
The other minor mistake that our technical support team sees fairly regularly is people forgetting to remove alkaline batteries from the equipment during long periods of storage. Over time alkaline batteries can leak acid into the battery compartment if not used for long stretches of time. This is the same for just about every electronic device. I’m sure that everyone here has experienced this in some form or another.
The problem is that the acid from batteries damaging a consumer electronics device like an MP3 player or a portable video game player costs you a couple hundred dollars to replace. The same damage on a sonde’s battery compartment will cost much more and will result in a trip to a repair center, which may impact your work schedule.
To summarize what we talked about here:
- Ion-Selective Electrode based sensors should never be stored in DI water, or they will lose their potency as their internal reagents leech out into the water.
- Don’t allow pH sensors to go dry.
- Always remove batteries from sondes for storage periods longer than a month to prevent potential battery acid leakage.
- Even though sondes are tough by nature, don’t leave thousands of dollars of equipment up to chance.
To learn more about how to properly handle and store your equipment, check out EXO University, for your on-demand training.
Additional Blog Posts of Interest:
5 Tips To Prevent Costly Mistakes With Your Sondes | Tip 1 of 5
5 Tips To Prevent Costly Mistakes With Your Sondes | Tip 2 of 5
5 Tips To Prevent Costly Mistakes With Your Sondes | Tip 3 of 5
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