Q: Our lab has just started using a new set of pipettes with our PCLM3 and our standard is showing different values, is there an explanation for this?
A: The calibration can be affected by the volume being delivered from the pipette used to measure the 500µl of standard. The response of the industrial instrument can be adjusted using the 500µl fine calibration control on the back of the instrument. This should be adjusted until the reading for the standard is ±3mg/l by adjusting this control and repeating the analysis of the standard until the value is within this range.
To ensure the same volume is delivered each time a measurement is performed the same pipette for each analysis should be used.
Q: How often should the electrodes be cleaned or replaced?
A: It is recommended that the electrodes are cleaned with the polish provided and replaced regularly depending on the instrument's usage. Frequency will also depend on the salinity and format of the sample. If the electrodes are being used regularly then the electrodes should be replaced every 6 to 12 months and more regularly if high concentration chloride samples are being used. The part codes for the electrodes are:
504 053 Pack of 3 silver anodes
504 052 Pack of silver electrodes (1 cathode, 2 detectors)
Both parts will be required to replace all the electrodes.