Test Methods Comparison

There are 4 main methods used to test water. The methods we will be comparing are:

• Photometer
• Titration
• Color Comparator
• Test Strip

 

Photometer

A photometer is a digital device that uses light to take its measurements. Photometers do not rely on the users to judge the results, and therefore can offer more consistent results. Some newer model photometers will link to your smartphone and allow you to store and send your results via email etc.

Pro	Con
Remove human error (no visual colour matching) Better result resolution  Best accuracy  Some link to your smartphone to manage results Easy to use	Price

 

Colorimetric Titration (Drop tests)

Colorimetric titration is a method that uses a chemical reaction to change the waters colour. The user then judges the colour compared to a supplied chart. 

Pro	Con
Low cost Good accuracy	Requires more technical ability Some calculations to be done manually

Colour Comparator

Colour comparators are similar to colorimetric titration. A chemical is added to the water and the colour change is comapred with the supplied colour chart. Comparators are designed to be easy to compare your sample colour and the chart. Colour comparators are relatively inexpensive and are a common commercial method of testing.

Pro	Con
Low cost Straightforward to use	Less accurate (lower resolution) Relies on user to judge colour and compare

 

 

Test Strips

Test trips are the most commonly used method of testing. They have small strips of chemicals that react to your water sample and change colour. This colour is compared to the chart provided to get the result. Test strips are cheap and straight forward to use. 

Pro	Con
Cheapest method Straight forward to use (dip & read) Good shelf life (compared to liquid)	Relies on user to judge colour and compare Least accurate

If you're prepared to spend the money, a photometer the best option for most situations. Removing the human element ensures your results are consistent and relies less on the operators ability. Their digital nature also means that you have more options for managing and analyzing your results. For more information about photometers check our Photometer selection guide.

For budget conscious users test strips are cheap, usually accurate enough for most applications and simple to use.