---
title: "Do I need to be at the site to perform the an on-site test?"
description: "Yes, you need to be at the site to perform the test. To ensure accurate results, take a sample of system water that is representative of the entire system. Let the water run for a few seconds before collecting the sample. Then, dip the test strip into the water for one second and remove it for analysis. For a detailed, step-by-step guide on how to use the Express Inhibitor Test, please refer to this guide"
url: https://help.fernox.app/en/articles/81-do-i-need-to-be-at-the-site-to-perform-the-an-on-site-test
collection: "General Information"
updated: 2026-10-05
language: en
alternates: [es, de, fr, fr-be, nl, nl-be, pl, ro, sv, tr, cs, sk]
---

# Do I need to be at the site to perform the an on-site test?

Yes, you need to be at the site to perform the test. To ensure accurate results, take a sample of system water that is representative of the entire system. Let the water run for a few seconds before collecting the sample. Then, dip the test strip into the water for one second and remove it for analysis.  For a detailed, step-by-step guide on how to use the Express Inhibitor Test, please refer to this guide

[

Submitting an Express Inhibitor Test

The Express Inhibitor Test provides a rapid on-site analysis of the concentration of all Fernox Protectors, and other molybdate based inhibitors, in central heating system water. After testing a PDF certificate will be generated automatically and sent to customers and chosen contacts. All the submissions will be stored in your account, so you can access them whenever you want.

](https://help.fernox.app/en/articles/71-submitting-an-express-inhibitor-test.md)