A company I am working with is using Sodium Bicarbonate in their water and using a twaddle hydrometer to measure the density. During our last Primus inspection they were told to list calibration procedures for the twaddle hydrometer. Unfortunately the only information I have is a chart somebody made with the solution temperature, twaddle hydrometer stem reading, and the % of the Sodium Bicarbonate. I dont know where the list came from but I believe this is what they based their SOPs off of. Would it be safe to say that calibration could be conducted by testing against the chart?
I am sort of at a loss here.