A dilution is required when the expected result falls outside of the test range. For example, if you expect the result to be 11 mg/L and the test is from 0 – 10 mg/L.
To perform a x2, x3, x4, x5 or x10 dilution you will need your sample, de-ionised water and a Palintest dilution tube.
To perform a higher than 10x dilution you will also need a 10mL syringe. This can dilute the sample up to 100 times.