intervals for the
How often should you calibrate your CITS?
Some Polar CITS owners may be unsure how often they should calibrate the instrument; some even question the need for calibration at all.
Polar Instruments has always maintained a policy of recommending regular maintenance and calibration to ensure that all products are performing as intended and within their published specifications. This is in common with all reputable manufacturers of professional test equipment.
For the CITS the calibration interval of one year is the longest time it is considered safe to wait between checks. A software reminder of this need for annual calibration is built in to help the user maintain this minimum level of maintenance.
Even an instrument that is rarely used may drift over time due to temperature and humidity cycling. If the instrument is in particularly high use this period of one year may have to be reduced as replacing cables and relays will affect the measurements made. Polar Instruments would not recommend replacing a relay without recalibrating.
Checking regularly with the supplied semi rigid 50 ohm test line is a good practice and will show any degradation due to faulty cables or static damage. However this is only valid at 50 Ohms and the full spectrum of impedance measurements needs to be checked occasionally as mild static damage only starts to show in ways that will not be seen at 50 Ohms. Calibration is a health check for the instrument.
Maintaining good test and calibration practices
Even the standards used
to calibrate the CITS need regular checking as simply handling them and using them
can cause mechanical forces which may result in changes over time. Connectors of
test lines are particularly at risk and these should also be checked regularly.