IC Controls recommends PT1000 (option -34) as it offers approximately 10 times better accuracy in most situations compared to PT100 (option -32).
pH or other liquid analysis sensors are often installed in humid environments with long signal lines, signal lead connections, and temperature fluctuations. PT100 changes 0.385 ohms per degree C; good clean signal lead connections often exhibit 0.2 ohms resistance to which 4 or 5 ohms resistance can be added from humidity resulting in about a 13 degree C temperature error. This is even before considering the copper lead resistance change effect on temperature compensation accuracy. In contrast, the PT1000 changes at 3.85 ohms per degree C translating into a clean connection error of about 0.05% and reducing humidity/corrosion induced temperature error to about 1.3 degrees C.
When IC Controls sensors are connected to a non-IC Controls analyzer, we strongly recommend verifying whether the analyzer can be used with PT1000 temperature compensation in order to achieve the better TC accuracy. If PT1000 is possible, option -34 should be specified in the IC Controls sensor. Only in the event that PT1000 cannot be used should option -32 be specified recognizing that temperature compensation and measurement will be less accurate.