Справочник Пользователя для eutech-instruments waterproof c401 colorimeter

Measurement: pH

 

 

C401/301/201/102/101 

 

 

 

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Samples may be collected in either plastic or glass bottles. It is advisable 
to wash the container with sample water before the sample is collected. 

For accurate results, analysis should be conducted as soon as possible 
after sample collection. 

The amount of sample used and the amount of reagent added is critical to 
obtaining correct test results. Ensure that the reagent is added in a 
consistent manner, with the dropper bottle being held vertically and 
squeezed slowly.  To increase the test accuracy, measure the 10ml 
sample and reagent using calibrated pipettes. Note: 20 drops of reagent = 
0.8ml. 

It is important to re-calibrate the meter to each new batch of reagent used, 
or if the reagent has not been used for more than a month. It is also 
important to occasionally check the results obtained with a colorless pH7.0 
buffer solution. If the result is outside the range pH6.9-7.1 re-calibrate the 
meter (please refer to section 3.4 pH). 

Due to the nature of the test method, a sample pH of less than 5.9 or 
greater than 8.2 may result in false readings.  Do not use this test method 
to analyze samples with a pH outside of the specified range.  

Chlorine concentrations of greater than 6ppm may interfere.  To remove 
this interference, add a crystal of Sodium Thiosulphate to the sample and 
mix, before adding the reagent. 

A colorless pH7.0 buffer (supplied) can be used to check the test accuracy 
and strength of reagent. 

 To check the accuracy of the meter:  Use a colorless pH7.0 buffer in 
place of the sample water in the above test method.  The result obtained 
should be in the range pH6.9-7.1 (please refer to instrument’s 
specifications for data on meter precision and accuracy). 

 Please refer to section 3.4 pH for details.