Klipspringer’s Laboratory Manager explains lead times, the process behind equipment calibration, calibration certificates, and more…

When it comes to equipment calibration, striking the balance between speed, thoroughness, and efficiency is crucially important.

Every year without fail, food businesses lose thousands in revenue when equipment is returned for calibration. Downtime forces production to slow, resulting in wasted labour, a depleted inventory, and a bottleneck in work.

At the other end of the scale, uncalibrated equipment is an even riskier alternative. It leaves food businesses at risk of low-quality products, non-compliant manufacturing or service processes, and unsatisfied customers.

With an in-house UKAS calibration laboratory that oversees more than 10,000 calibrations annually, we are regularly asked a range of questions about equipment calibration, from the process of recalibrating equipment to the factors impacting lead times.

Based on an interview between Radek Tameczka (our Laboratory Manager) and Alex Blair (our Content Lead), this article answers the following FAQs:

equipment calibration
Radek Tameczka, Laboratory Manager at Klipspringer

What is equipment calibration and why is it important?

Drawing on his 15 years’ experience in the industry, Radek pointed out a key misconception surrounding calibration. “Calibration is often mistaken to mean adjustment. That’s not always the case. In many instances, calibration means verification of what the instrument reads at a very specific point.”

For example, a thermometer calibration involves a verified analysis of its temperature accuracies. Most laboratories verify the thermometer’s accuracy at three different temperature points, such as -18°C, 0°C, and 100°C.

If the instrument is adjustable, then the calibration process can involve modifications. If it is not adjustable, equipment is returned with a calibration certificate stating any divergence, such as -18.2°C, 0.3°C, and 100.5°C.

calibrating tools
laboratory calibration
UKAS calibration certificate

The importance of this cannot be overstated. Yes, certification proves that your instruments are traceable to a UKAS-accredited standard – in Klipspringer’s case, international standard ISO/IEC17025. Calibration certificates also enhance company adherence to food safety standards and are one of the most common requests made by assessors during audits.

But, most crucially, certificates also explicitly demonstrate the exact accuracy of an instrument. Neither subjectivity nor error are tolerable when it comes to food compliance. Customer safety is at risk – particularly with temperature, where the difference between safe and unsafe food could be as little as one degree.

How do I specify the equipment calibration I require?

Simply contact the Klipspringer Service Department on 01473 461800 or service@klipspringer.com with the following details:

calibration of testing equipment

1. What is being calibrated? 

Thermometer, Data logger, Verifier, LazaPort, Humidity Meter ect.., with serial number.

2. What type of calibration do you require?

Normally this is UKAS, however we do offer a Caltrac option if preferred.

3. How many and which reference points do you require calibration to?

4. Once the above details have been confirmed, your quotation and returns form will be emailed to you.

Most calibrations are completed in just 2-3 working days.

How often should I calibrate my equipment?

In conversation with Radek, he outlined four specific factors that determine the necessary frequency of calibration. These are:

1. Equipment type

In general, most equipment requires consistent calibration, although, logically, certain types of instruments require recalibration on a more regular basis than others. Humidity meters, refractometers, and callipers are all examples of instruments that should be frequently recalibrated.

2. Usage

A general rule of thumb here: as a piece of equipment receives more use, the frequency of its calibrations must increase proportionately. For example, thermometers are usually expected to be calibrated at least once a year – but Radek says some food businesses send their units in for calibration every 4-6 months because their usage is so high.

calibrating tools
equipment calibration

3. Likelihood of readings changing without recalibration

For equipment which sees regular shifts in readings, more frequent calibration is required. These might include data or process loggers. Conversely, it is not as essential to repeatedly recalibrate instruments which maintain the accuracy of readings for longer.

4. Capacity to calibrate the equipment on-site

Some food businesses are able to calibrate their equipment on-site. For instruments like pH and conductivity meters – which are expected to be calibrated daily – it makes sense to keep the majority of these verifications in-house, with occasional external confirmations.

Radek underlined the importance of an external validation procedure to confirm that units are still working within their specification. Cross-checking confirms in-house calibrations and drives compliance.

In a recent conversation with Ben Foster, an Equipment Engineer at Pharma, Radek was told that they calibrate their pH meters in-house every day. However, for traceability and good practice, Pharma also sends all pH meters to a third-party at least once a year to confirm these readings and ensure the highest safety standards.

While it is impossible to provide an exact calibration timeline for all scenarios, a quick appraisal of your equipment based on those four factors should give you an approximate idea of how often you should calibrate your instruments. If you want a more personalised idea, feel free to contact our Calibration Team: 01473 461800.

Equipment calibration: how do I return my equipment?

The below outline is based on our internal calibration process at Klipspringer, overseen by Radek as Laboratory Manager.

equipment calibration

Calibrations that fall within the UKAS-specified -30°C to 150°C range are always carried out internally, according to the following procedure:

1. The customer communicates with the lab team and raises a quotation

2. The customer sends their equipment to the laboratory

3. This equipment is booked in; the customer is sent an email confirmation, specifying exactly what the lab team is going to do with the equipment

4. If the equipment is booked in for UKAS calibration, the customer will receive an email with confirmation of temperature point the unit will be calibrated at

5. A lab technician is designated to the task – they either begin the laboratory calibration immediately, or carry out any necessary technical repair beforehand

6. Equipment sent in for UKAS calibration will need to be stabilised at an ambient temperature of 20°C ±4 for up to 24 hours before performing the calibration

7. Once repaired and/or calibrated, a certificate is issued to the customer and uploaded to the Audit Portal

8. The laboratory calibration is passed onto the Service Team, who send an email quotation to the customer to confirm any final details

9. Following customer approval, equipment is returned to the customer, usually on the same day, or at least within three working days

humidity calibration
A humidity calibrator

How long should the equipment calibration process take?

Defined as the time elapsed between the start and end of the calibration process, calibration lead time is a crucial metric in the food industry used to calculate how quickly and efficiently your equipment can be calibrated, returned, and operating once more.

By making enquiries among our customers, we ascertained that, on average, most companies in the industry operate with calibration lead times of 4-7 days. Sometimes these turnaround times are as lengthy as 2-3 weeks!

According to Radek, there is no hard-and-fast rule for lead times. But there are two factors that markedly influence lead times: the number of calibration orders at any one time, and the resources available to manage them.

laboratory calibration
The Klipspringer Lab

It is also true that some companies simply prioritise calibrations more than others. When asked why Klipspringer are able to guarantee that all in-house calibrations are fully completed within three working days, Radek replied:

“We have several skilled lab workers constantly on the calibrations, completing each with meticulous attention. It comes down to efficiency and experience.”

Which equipment types need calibrating?

In short, the stringent compliance regulations of the food service and production industries necessitate regular verification of the majority of equipment used in kitchens, warehouses, and production lines. This is particularly true since the BRCGS announced Issue 9 of the Global Standards in Food Safety, auditable from 1 February 2023.

Below is a comprehensive list of various instrumentation types that Radek stipulated as requiring consistent calibration.


  • Data Loggers
  • Process Loggers
  • Liquid ‘In-Glass’ Thermometers
  • In-House Thermometer Verifiers (also known as Temperature Simulators)
equipment calibration


  • pH and Conductivity Meters
  • Reflectometers (measure the reflectivity of objects)
  • Anemometers (measure the speed of wind or gas currents)
  • Refractometers (measure the index of refraction)
equipment calibration
equipment calibration


  • Handheld Units
  • Loggers
  • Dry-Block Calibrators
equipment calibration


  • Callipers (measure the dimensions of an object)
  • Scales and Weights
  • Oil Quality Measurement
  • Hygiene Monitors
  • Light Meters
  • Gas Analysers

Radek emphasised that, while this list encompasses most of the instrumentation most frequently calibrated at Klipspringer’s in-house lab, it is not exhaustive – other types of equipment will also need calibration.

If you’re unsure about anything calibration-related, please contact our customer service team at: 01473 461800. A member of our team will consult one of our Calibration Experts about your specific requirements, before giving you all the relevant information.

Alternatively, you can read another research-led article we wrote detailing how to understand your UKAS calibration certificate.

You can also share your details using the contact form below.

If you would like further guidance relating to the advice shared in this article, the Klipspringer team would be happy to help. Share your details below to arrange a free consultation.