Calibration of SUS p H electrodes Hamilton SUS

Calibration of SUS p. H electrodes

Hamilton SUS p. H electrodes Quality Declaration : All sensors delivered with Quality Declaration The Quality Declaration contains all information needed for start-up 2

Hamilton SUS p. H electrodes Quality Declaration : Zero point Most equipment (controllers or transmitters) need zero point value and slope The zero point value is the m. V value at p. H 7, directly provided in the declaration 3

Hamilton SUS p. H electrodes Quality Declaration : Slope The slope is calculated based on zero point value and p. H 4 reading according to following formula (all m. V values at 25°C) : Slope= [E(p. H 4. 01)-E(p. H 7. 00)] / [(p. H=4. 01) – (p. H=7. 00)] In previous example : Slope = (181 – 4)/-2. 99 = -59. 2 m. V/p. H 4

Hamilton SUS p. H electrodes Quality Declaration : Zero point as p. H value for 0 m. V Some equipment may need the slope and instead the zero point, they require the p. H value to get 0 m. V. This one can be calculated as follows : p. H(E=0 m. V) = [p. H 7*E(p. H 4) – p. H 4*E(p. H 7)]/(Ep. H 4 -Ep. H 7)] = In previous example : p. H(E=0 m. V) = [7. 00*181 – 4. 01*4] / [181 -4] = (1267– 16. 04) / (177) = 7. 067 5

Hamilton SUS p. H electrodes During process calibration : Some processes may require p. H adjustments of the electrode during process and without removing the electrode from the vessel. This procedure is called “product calibration”. The user takes a sample of medium (through sterile sample valve) and makes a reference p. H measurement (in lab). In case the reference value differs from process value more than a user pre-defined tolerance, an adjustment is required. It consists of an offset adjustment, the slope remains unchanged. Hamilton SUS electrodes can be handled is this way, the procedure however must be supported by the controller / transmitter. 6

Thank you for your attention! Hamilton Company, Reno / USA Hamilton Bonaduz AG, Switzerland 7