After you submit your results to our results server, you receive two mails: one with the assigned evaluation number and another saying that the submitted mail contained no attachment.

This error message is usually caused by an out-of-office assistant (or another automatic reply rule) that is active when you send the mail or shortly afterwards.

Because the results server confirms receipt of your mail, the out-of-office assistant automatically replies to our system with an out-of-office message, which has no attachment. Our system then reports that you sent us a message without an attachment.

A large number of parameters is offered for each individual proficiency test.

The parameters intended for examination in a proficiency test are indicated, among other places, on the enclosed result data sheets.

You can submit results for all the parameters offered, but you do not have to.

You should only examine those parameters from the specifications that are routinely examined in your laboratory.

The order numbers (e.g. 18-40) of the available test items always follow the pattern "YY-ID". YY stands for the year in which the test item was used, and ID stands for the identification number of the corresponding proficiency test.

By default, we send Excel spreadsheets in *.xlsx format. They can also be downloaded from our website.

If you cannot send Excel spreadsheets as email attachments, you can proceed as follows:

1. Enter your results into the Excel spreadsheet as usual and save it.
2. In your file explorer, change the file extension *.xlsx to one that your security settings consider harmless (e.g. *.txt). Do not open the file again afterwards.
3. Send us an email at edv@lvus.de and attach the renamed file as usual.
4. You will receive a confirmation email with your assigned evaluation number. Please note that this requires some processing time.

We have decided against such a system for data protection reasons. With our current procedure, your results are stored on a server that only we control.

ISO 13528:2015, which applies to the evaluation of proficiency tests, proposes a minimum of 11 participants. If the inter-laboratory standard deviation calculated during the evaluation and the target standard deviation used to assess the results are about the same, the influence of the uncertainty of the reference value is acceptable: its value (in z-scores) is then 0.3, which corresponds to 10 % at an "action level" of z = 3.

LVU mainly offers proficiency tests in which several parameters can be examined. Experience shows that not all participants submit results or process all parameters, so in practice more than 11 participants are needed to evaluate the parameters. LVU therefore only carries out a proficiency test if an evaluation will be possible on the basis of the registrations received.

Unless requested otherwise, results should always be reported as the free substance (e.g. saccharin not as the sodium salt) and without water of crystallisation.

Unless stated otherwise, results should always refer directly to the sample and not to the dry matter (even if, for example, methods in the Official Collection under § 64 LFGB provide for this). Results should, as far as possible, not depend on other results (e.g. the determined water content).

The number of decimal places requested is usually higher than customary, so that rounding effects are avoided in the evaluation.

For some results, parameters are chosen that are derived from the analytically determined parameters by multiplying with factors (e.g. crude protein from "basic nitrogen", butterfat from "HBSZ", "free butyric acid" or "butyric acid esters"). This is usually because the directly determined parameters are not legally regulated. The comparability of the results is nevertheless ensured, as the conversion factors are fixed or the factors used are requested, so that the results can be normalised afterwards.

Our PTs are available in German only.