DRINKING WATER: PHYSICAL-CHEMICAL A /REF. 990001/
In the following tables you can see the dates on which the rounds take place:
| ROUND 1 | ROUND 2 | ROUND 3 |
|---|---|---|
| WEEK 8 16th February 2026 |
WEEK 21 18th May 2026 |
WEEK 39 21st September 2026 |
| Aluminium | Arsenic | Calcium |
| Ammonium | Chlorides | Chromium |
| Antimony | Colour | Combined Chlorine |
| Bicarbonates | Iron | Copper |
| Boron | Mercury | Fluorides |
| Cadmium | Nitrites | Free residual Chlorine |
| Conductivity at 20 ºC | Oxidability | Lead |
| Langelier index at 20ºC | pH | Nickel |
| Magnesium | Potassium | Sulphates |
| Manganese | Selenium | Total Chlorine |
| Nitrates | Zinc | Turbidity |
| Sodium | —– | —– |
| Uranium | —– | —– |
You will find detailed information in our Proficiency Testing Scheme Catalogue.
You can find the guideline ranges of concentration here.
For any further information, please contact ielab at: comercial@ielab.es.



