There are many different methods that can be used to analyse water. Which method you choose is ususally dependent upon several factors such as cost, accuracy and technical requirement. Below are the six main methods that we provide in our kits, though it should be noted that this list is not exhaustive and other methods can be adapted to your needs for field or laboratory based work.

Please click on a method below or on a tab above to get more information about that method

Test Strips

Test Strips, although not the cheapest option, are designed to be used where a rapid, guideline result is required.

The accuracy of Test Strips is dependent on the range covered but can only be guaranteed to be the colour swatch above or below any given result. For this reason Test Strips should be used as a semi-quantitative or rough guide result and not as an accurate analysis.

Test Strips are often used for pH, chlorine and peroxide.

• No reagents
• Hazard free
• Semi-quantitative
• Easy to use
• Rapid result

Tube Tests

Tube Tests use a single reagent for the analysis of a number of key parameters and are the most economical option for testing.

The accuracy of the Tube Tests depends on which type of method it employs. This could be a colour comparison to a chart whereby the colour matched can only be guaranteed in a similar manner to test strips or a drop test using a single reagent giving an accuracy between 10 - 20%.

Tube Tests are commonly used for Hardness Stop/Go and Chlorine.

• Single reagent
• Low cost
• Easy to use
• Rapid result

Comparators

The Comparator is the choice of many when a mid-range cost solution is required for a single or low number of parameters.

A sample of water is taken in two tubes, reagents added to one tube – the other is the blank. The parameter specific disc is put into the comparator with the two tubes and the colour is the sample tube is compared to that on the disc.

There are currently two different styles of comparator available on the market, plastic and glass, with a significant price difference between the two:

• Plastic discs with a continuous colour scale and limited shelf life.
• Glass discs with individual glass standards for each division, guaranteed for life.

The accuracy of the comparator has been accepted for many years as a reasonable solution for field analysis giving an accuracy in the region of 10 - 20%. Again the result is only guaranteed to be within one division either way of the actual result.

Comparator tests are most often used for chlorine, bromine, chlorine dioxide and molybdate.

• Easily portable
• Mid-range cost
• Simple methodology
• Quick result

Drop Tests

Drop tests are used frequently for high range analysis, and although they were originally derived for customer tests they are commonly used as the engineers test of preference given their accuracy, speed of use and simplicity.

The Drop test technique is a basic form of the standard titrimetric procedure performed in laboratories using burettes and relies on the dropper tip delivering a known amount of liquid per drop.

App-Chem drop test chemistries can also be adapted to our customers special requirements and bespoke tests made on request for customers own products.

Drop test accuracy ranges from 10 - 15% depending on individual technique.

Common parameters determined by Drop Test are hardness, alkalinity, nitrite, sulphite and chloride.

• Easily adaptable
• Low Cost
• Easy to use
• Quick result

Digital Titrator

As with drop tests the Digital Titrator method derivatives from the laboratory burette method. However instead of a dropper bottle this method uses a cartridge of concentrated titrant and a digital titrator which dispenses the chemical in tiny quantities allowing far greater precision and more accurate results.

The titrator is used most often with hardness and alkalinity.

• High initial capital outlay
• Low replacement reagents costs
• 1 - 5% accuracy
• Built-in interference mitigation

Photometers

Photometers are pre-set instruments with programs for dozens of parameters. This removes any interpretation of results and the accompanying loss of accuracy this inevitably entails. In addition some models can have additional parameter programs added by the user and can also be connected to a computer, allowing data logging of results.

Photometers are the best method for determining metal concentrations.

• High initial capital outlay
• Mid-range replacement reagent costs
• Consistant, reliable results
• 10% accuracy
• Some have computer compatibility