Open Colorimeter Tests

Open Colorimeter Tests

Colorimeters are extremely flexible and easy to use lab instruments. Below are just some examples of how colorimeters are used:

  • Water quality testing: there are a wealth of colorimetric assays for measuring water parameters such as water turbidity, chlorine content, pH, water hardness, phosphate content and more
  • Monitoring freshwater & saltwater habitats: wildlife and conservation biologists as well as aquarium & aquaponics hobbyists can use colorimeters to monitor levels of ammonia, nitrate, nitrite, phosphate in a habitat
  • Soil measurements: colorimetric assays can be used to measure environmental pollutants and contaminants such as lead, oil, diesel and pesticides in soil
  • Biochemical assays: Standard methods in labs for measuring protein employs the Bradfords reagent and measurement assay

Using the default tests

Currently we have four default tests that are included with the colorimeter firmware. Blue food dye 1, Ammonia, Nitrate and Nitrite.

Open Colorimeter: measuring blue food dye in sports drinks
Goal: Use the Open Colorimeter to experimentally calculate the molar extinction coefficient of FD&C Blue #1 Beer’s Law states that absorbance of a sample (Abs) depends on the molar concentration (c), light path length in centimeters (l), and molar extinction coefficient (ε) for the dissolved substa…
Ammonia-API colorimetric assay
Colorimetric assay for measuring ammonia levels using API test kit. Range: 0-8ppm
Nitrate-API colorimetric assay
Colorimetric assay for measuring nitrate levels using API test kit. Range: 0-50ppm
Nitrite-API colorimetric assay
Colorimetric assay for measuring nitrite levels using API test kit. Range: 0-2ppm

Below is a short video demonstrating how to use the default ammonia test.

The steps for all default tests are basically the same:

  • Make sure you have the correct LED board installed. Check the instructions for each test.
  • Navigate to the menu and select the test you want to use
  • Place your control or blank sample in the colorimeter and press the blanking button
  • Place your sample in the colorimeter. The display will show the result in appropriate units.

Request an assay

We have previously measured phosphate, sulfate, calcium, pH, alkalinity, iron, lead and potassium with the Educational Colorimeter Kit and are in the process of repeating some of these tests with the new Open Colorimeter. These and other tests will be documented in the Table above so keep checking back as new tests get added! However, we also want to hear about tests that the community are interested in. Use this form to request an assay to be added to the Open Colorimeter measurement library.

Sharing tests with the community

We have started to build out the colorimeter library with tests as shown in the Airtable database below.

Our goal is to build this out with tests developed/shared by the community! To add your test, please fill out this form.