Dairy Calibration Standards

Calibration & Proficiency Products & Services

LABTEK Services has been supporting the UK Dairy infra-red and photometric analyser for over 30years.

In 2008, as a result of not being able to source accurate and reliable calibration samples for our engineers, we decided to introduce our own.

We now partner with Qlip (Netherlands), the largest accredited milk testing laboratory in Europe.

Milk and Dairy Calibration Standards

Making sure you get the readings you need on your milk products is our priority.  We use Qlip to provide us with the very best and most accurate control samples for all your Fat, Lactose & Protein tests to ensure that your milk and dairy composition is exactly what you think it is, and what is required by ISO governance.

Our Qlip control samples are correct to the following levels of certainty.

  • Fat:  +/- 0,01%m/m
  • Protein: +/- 0,02%m/m
  • Lactose: +/- 0,02%m/m 

These levels comply with the NEN-EN-ISO 1222 (Fat), ISO 8968-1 (Protein) and ISO 22662 (Lactose).

Pilot Sample Sets

The Qlip calibration sets have proven to be popular. A number of national milk groups and internationally recognised institutions are now using us for their monthly calibrations  and instrument monitoring.

What sets us apart? Labtek engineers are able to assist both product support and instrument support if required.

We can offer a range of calibration sets that are suitable for all infra-red dairy analysers, such as the Lactolyser, Lactoscope range, Foss Machines, and Bentley Analysers:

  • Raw Milk Fat % – 7 samples ranging from 0-6%
  • Raw Milk Protein % – 5 samples ranging from 2-5%
  • Raw Milk Lactose % – 5 samples ranging from 3-6%
  • Skim Milk Calibration Set Fat, Protein & Total Solids
  • 0.05%,1.5%, 3.5% & 4.2% Control Samples
  • Cream Low Fat % – 5 samples ranging from 23-31%
  • Cream High Fat % – 6 samples ranging from 33-50%
  • Cream Total Solids % – 6 samples ranging from 39-48%
  • Raw Milk FPD – 8 samples
  • Whey Fat % – 5 Samples ranging from 0.05 – 0.35%
  • Whey Protein % – 5 Samples ranging from 0.5 -1.1%

Understanding Calibration and Inter-correction of Infra-Red Instrumentation

We understand the need for precise measurements when testing the composition of your dairy products.

Whenever a machine leaves the factory, it will have been calibrated against certain criteria on a wide range of fats, lactose and protein samples, but this will wane over time through wear and tear. How do you know that the machine you are using is still as accurate as it was on day one?

A well calibrated infra-red instrument, should have a slope close to 1.0 and a bias close to zero on all milk channels.

Keep Your Quality High

We are seeing an increasing number of calibration sample sets that simply don’t have the level of accuracy and stability that our qualified engineers would recommend for instruments. They can have very little range in their protein and lactose samples and this tends to confuse self-calibrating instruments.

Commercially Available Samples e.g. PROTEIN 3.30 – 3.60% LACTOSE 4.45 – 4.75%

LABTEK QLIP Samples e.g. PROTEIN 2.00 – 5.00% LACTOSE 2.97- 5.79%

Any instrument that has a slope of less than 0.75 and a bias greater than 0.75 either has a fault or is incorrectly calibrated. This is true for Fat, Protein & Lactose of any standard milk (i.e whole, semi or skimmed).

An Example:

If the ‘commercially available’ samples mentioned above, were used when calibrating your machine and all the samples above 3.4% had a -0.03 bias and all the samples below 3.4% had a bias of +0.03 then it might appear to be a good calibration. The + & – would cancel each other out and you would end up with a zero mean bias.

However a self calibrating instrument has to choose a best line of fit for these samples and we have seen on many occasions can actually end up with a bias of 3.50 and a slope of –0.05.

What would this mean to your results:

If you analysed water the instrument would read 3.5%, if you analysed milk with a true protein of 3.5%, the instrument would read 3.50%.

Clearly something is not correct!

Now Print out the slope and bias’s of your instrument, are they showing slopes of less than 0.75 or bias greater than 0.75? if yes then you need a solution to your calibration techniques.

The Solution?

LABTEK Milk Calibration Standards:

  • FAT RANGE 0.07 – 6.00 %
  • PROTEIN RANGE 2.00 – 5.00 %
  • LACTOSE RANGE 3.00 – 6.00 %
Protein Samples P1-P5:

The graph shows a set of LABTEK Protein Samples. It extends the testing range compared to the graph of the commercially available samples (above). The slope through the true testing range of 3-4% is close to 1, therefore a sample of water analysed would be close to 0.00 and the true 3.5% Protein would read 3.5%

Product Code MCS7 : Milk Fat Calibration Samples* (7)
If fat is your only concern we have a seven sample set from skim to 6% in 1% steps these have protein and lactose results but not with extended ranges.

Product Code MCS17 : Milk Fat (7)/ Protein(5) / Lactose(5) Calibration Samples*

This set of 17 samples provides a comprehensive range of samples for the three major components of Milk. Examples of which are given below:

Internationally Recognised

Qlip’s chemical and microbiological laboratory processes more than 400,000 samples per year. Testing mainly applies to raw and heat-treated milk, cheese and cheese products, butter and milk fat products, powdered milk products and infant a formula. Our testing is nationally and internationally recognised and accredited.

Qlip are also an accredited testing lab, in their own right, and currently analyse more than 2.3million herd samples per year. Qlip also performs hygiene checks on the transport from dairy farms to the processing plants. Dairy farmers and breeding organisations base their policies on milk data from individual animals. For
this purpose, Qlip analyses more than 200,000 milk samples from individual cows on a weekly basis. Also,

each year more than 10,000 reviews and audits are done throughout the chain.

The Standard for Quality Assurance in Dairy

Qlip has over 30 years of experience in  control samples and calibration products for analytical instruments.

Currently over 80 facilities worldwide are using Qlip samples to test and calibrate their mid-infrared instruments.

Our products are seen as the ‘standard’ for several respected global dairy laboratories and our quality is constantly assured through collaboration with exclusively accredited reference labs and leading global mid-infrared instrument manufacturers.

Through a process of benchmarking and regular proficiency tests, Qlip is always looking to innovate and improve its products and services.

Based on our knowledge and expertise at Labtek, we can see that Qlip supports customers to achieve the best results.