Most instruments are typically subjected to some fairly rough treatment — bouncing around in the vehicle, dropped, knocked, fuses are blown and so on. Even if they’re treated carefully and not bashed around, changes in ambient temperatures, humidity levels, condensation on those cold winter mornings, and deteriorating component tolerances will cause a shift in any electronic measuring equipment readings over time.
For these reasons, regular calibration is advised and if required, adjustments, to ensure the outputs are accurate and therefore dependable.
Here are 9 more reasons why calibration is critical in the electrical industry;
- Regular calibration can extend the life of test equipment and instruments. Regular calibration can often pick up any problems with instruments early in their development, that can be rectified, easily and affordable. If left unattended, the problem may become a serious issue, which may cause component failure or board damage inside your instrument.
- As an electrical contractor, you can increase the actual and also perceived value and quality of jobs that you perform, by providing test reports for your work, which should list your test instrument/s used in performing those tests, as traceability information. You can also provide a copy of the calibration report/s for the instrument/s used, further increasing the credibility and perceived value of your work. Wouldn’t that set you apart in the market!
- The regular calibration of your instruments could protect you from possible litigation or insurance problems. If there is ever the unfortunate incident where you or your employees cause or sustain personal injury, death or property damage – insurance claims will not be paid out if un-calibrated equipment is deemed to be a contributing factor by the assessor. Furthermore, a litigator will pursue criminal charges against the responsible person that allowed work to be conducted with un-calibrated equipment if deemed negligent.
- It is a requirement of ISO9001:2015 that equipment used for testing and measuring must be regularly calibrated to the manufacturer’s specifications, and that records be maintained. Those records must also show traceability information to the test equipment used, company, technician and much more.
- When performing a calibration, an IUT can often be proved accurate on one part of the range on any given function, and still, fail in other sections of that same function. Therefore, if an IUT is functioning at 240V AC when checking at a ‘known source’ or on a checkbox (both of which are sometimes substituted for calibration), it doesn’t by any means ensure that it is correct or functioning at all at other voltages, including 415V AC. Verification that AC Voltage is functioning also doesn’t mean that any of the DC function, or any other functioning, is whatsoever is working or accurate.
- It is a requirement of Worksafe QLD. Electrical safety code of practice 2013: Managing electrical risks in the workplace states: “work on plant or equipment should not begin until tests have confirmed it is safe to do so. The calibration of any instruments required to test isolation procedure should be checked before use.”
- It is a requirement from the ETU VIC. They state “all equipment used for testing an installation must be regularly calibrated to the manufacturer’s specifications”, (Alert #9, 2001. Reviewed 2008).
- It is a requirement of AS/NZS3000. The standard doesn’t mention calibration, but it does require testing to confirm certain readings, within certain accuracies. For example, it requires that system voltages are tested, and that they are confirmed to be within a certain tolerance (+10%/-6% in Aust, +6%/-6% in NZ). Without performing proper calibration on the test instruments to be used, which allow you to know the accuracy of your instruments, you are not able to ascertain if any installation tested with your instrument, meets that AS/NZS3000 tolerance requirement (you need to know the uncertainty of your instrument to do that, something that is provided on calibration reports). In more detail, Clause 1.6.2(c) of AS/NZS3000 outlines that the nominal voltage and tolerances for low voltage supply systems and electrical installations are – a. For Australia, 230/400 V +10% to -6% and b. For NZ, 230/400 V +6% to -6%. AS/NZS3000 also requires Earthing continuity to be tested (Clause 188.8.131.52) and confirmed as not more than 0.5Ω. This again means calibration is required, ensuring the instrument is accurate, in this case to an implied accuracy and resolution of 0.1Ω. Further tests that require a known instrument accuracy (meaning regular, traceable, calibrations which will provide that information on the certificate of calibration) are Insulation Resistance and Loop Impedance. You cannot comply with any ‘shall be no more than’ or ‘shall be within +/-‘ requirements of the standard without knowing your test instrument accuracies, and confirming them regularly.
- It is a requirement of the Qld Electrical Safety Regulation 2013. It states “a person conducting a business or undertaking must ensure that electrical work on energised electrical equipment is carried out by a competent person who has tools, testing equipment and personal protective equipment that are suitable for the work, have been properly tested, and are maintained in good working order. Failure to comply can result in a maximum of 40 Penalty Points”. The only way to properly test electrical safety equipment and instruments is to perform full HV testing or calibration. The Electrical Safety Regulation 2002 even went so far as to specify a six monthly test frequency, and this should still be followed in order to adhere to best practice, and minimise liability. This is also recommended by the National Electrical Contractors Association (NECA).
Don’t risk it, set yourself apart in regards to quality and safety, and make sure you calibrate today and on a regular basis. The cost is more than is outweighed by the reduced risk, and the increased reputation from doing so.