Every day, our technicians assess a wide range of thermometer models sent in for repair. Several months ago, they began drawing up a list of the most common causes of damage to these probe thermometers they were inspecting.

Now, our technical team love to repair probe thermometers – and, with external accreditation from UKAS, ISO 9001, and BRCGS, it’s clear that they are rather good at it.

Even so, our technicians insisted that we compiled and published this concise article. Drawing on their combined experience, it outlines the three most common causes of probe thermometer damage and offers tangible ways to avoid them.

Read on for more.

The Klipspringer Lab

Cause #1 - Water Ingress

Moisture is inescapable in food factories. Even if the production area is not technically a wet environment, excess moisture can be caused by a number of factors, including:

  • Build-up of condensation from cooking processes
  • Steam from machinery
  • Hygiene washdowns
  • Rapid cooling processes (e.g. blast chillers/freezers)

Moisture poses a serious threat to instrumentation, thermometers above all. Within each unit, electronic wiring (primarily the PCB, or Printed Circuit Board) is crucial to the thermometer working correctly.

When water gets into your probe thermometers, it corrodes the PCB, which causes accuracy to drift. Initially, this drift may be very subtle, but it will soon worsen until the thermometer’s readings are wrong.

Given the importance of probe thermometers to ensure food is cooked to the compliant temperature, this could have serious ramifications for your business in the form of a non-conformance or harmed customer.

You might be thinking that this is true, but surely your IP67-rated thermometer is protected from water ingress?

IP or Ingress Protection ratings give customers a clear indication of an item’s resistance to various types of unwanted intrusion. Typically, it encompasses three key metrics:

  • Resistance to ingress, accidental or otherwise, by the user
  • Resistance to ingress from foreign bodies (e.g. dust, dirt)
  • Resistance to water ingress

Many thermometer specifications state IP67 rating. But you also need to check that both the thermometer unit and probe connector are IP67 rated. Without this, supposedly waterproof thermometer units still offer an access point for moisture to creep in.

In some cases, damage done to thermometers via water ingress is unrepairable. Questioning if your thermometers are exposed to moisture and if they are adequately protected can save your team a lot of time, effort, and money in the long run.

Cause #2 - Probe Cable Damage

Probe cables are considered a necessary part of a probe thermometer. Thermometers without cables are available (such as stem thermometers) but are rarely practical in production areas.

There are several forms of damage to probe cables that are not visible to the untrained eye. The most frequent are:

a) Fiddling

Fiddling with thermometers while not in use is probably the most common cause of damage. Inadvertently, many operatives play with the probe cable by twisting it or swinging it around. This stretches the electronic wire to snapping point, severing the electrical connection.

b) Snagging

Snagging most commonly occurs when the user puts the thermometer down and drops the probe, or when the user accidentally drops the thermometer and catches the probe as it falls. This puts excessive tension on the electronic wires inside the cable. If repeated too many times, the electronic wire inside the probe cable will snap.

c) Using as a prop

Fundamentally, probe thermometers are not designed for jamming doors, hatches, or windows open! Like snagging, this causes the electronic wires inside the cable to sever over time. The probe becomes unusable and must be replaced.

A thermometer instrumentation station

Unfortunately, all three types of probe cable damage are either unrepairable or not cost effective to repair. However, they can be avoided thorough team training and designating a purpose-built home to keep your thermometers out of harm’s way, as depicted above. Shadow boards which store instrumentation utensils are one of the most popular solutions in the food industry – read more about shadow boards here.

Cause #3 - Impact Damage

As fine-tuned electrical devices, thermometers require careful upkeep. Much like other electrical equipment, from home appliances to smartphones, thermometers are highly susceptible to impact damage.

For example, if a thermometer is dropped from waist height onto a hard, solid floor, it is likely to ‘shock’ the internal electronics. A subsequent effect is water ingress, as the thermometer’s outer layer is damaged and no longer resistant.

Our technicians observed that impact damage is actually likeliest to occur when the thermometer is not in use. Protective covers (e.g. the silicone boot) help to mitigate damage by cushioning the force of any impact. As with probe cable breakage, impact damage can also be circumvented by suitable thermometer storage.

Identifying these three causes of damage and implementing targeted methods to prevent them can significantly increase the accuracy, lifespan, and reliability of your thermometers. It also results in reduced costs, inconvenience, and time wasted for hectically busy hygiene teams.

Even with these methods in place, it is still important to make thermometer calibration a regular part of your equipment routine.

Radek Tameczka, Laboratory Manager at Klipspringer

For more information, we’ve compiled a complete guide to equipment calibration based on an interview with Radek Tameczka, Klipspringer’s Laboratory Manager, who has more than 15 years’ experience in the industry. You can also view Klipspringer’s instrumentation range, including our widely praised thermometers.

Calibration Guide
Service & Calibration