You would have noticed that the latest standards and technologies used by devices under test require extremely higher levels of accuracy than a decade ago. Since modern calibration equipment needs to test and maintain these high levels of standards for test equipment that are already extremely accurate and precise, these need 
to deliver performance many times greater than the equipment being tested. Adith Vishwa, manager – repair and calibration, Rohde and Schwarz, explains, “Equipment required for calibration has to be up to four times better that original equipment.”
“Calibration equipment is the ideal instrument preserved under standard ambient conditions in labs,” says Abhijit Shah, assistant manager – service and calibration, Testo India Pvt Ltd.
Comparing this with regular measurement instruments, “These experience several shocks and drifts in atmospheric aspects, as these are carried to several locations with different conditions,” he adds.
Since calibration instruments are kept in their ideal state, these are more accurate and precise as compared to measurement equipment. Vishwa adds, “Standard has to be maintained in these equipment, hence these are kept under stable environments.”
T&M riding the smart wave
Other than maintaining optimum temperatures for highly sensitive calibration-standard equipment, these are now becoming smart devices, too. Hiren Thaker, head – service, Rohde and Schwarz, explains, “The devices are now becoming intelligent.” This is most certainly a welcome step towards the smart wave. “Equipment today have features for self-test and calibration,” he adds.
This also makes the equipment interesting, as once the measurement begins to waver from the actual value, the device would either give an alarm so that proper measures can be taken, or self-calibration would bring the measured value close to the actual value.
Featuring safety. At a primary level during the development stage precautions should be taken to make the instrument more robust and resilient, so that it can resist external impacts and the sensors can also be kept safe.
Protection caps (plastic or metal, depending on equipment and requirement) are also incorporated in calibrators to ensure safety during measurement. “Avoiding human interface with proper coating ensures that the body is rugged and reliable,” explains Shah. “These equipment are now more rugged compared to before,” adds Vishwa.
The challenge in Calibration Equipment
With the employment of T&M equipment in a multitude of applications, various forms of calibrators (calibration equipment) have come to be in high demand. However, some challenges will have to be overcome in order to get the best in calibration.
Mobile calibrators. A trend developing for maintenance, repair and operation is the use of handheld equipment. In order to consolidate calibration in handheld equipment, “There is a need to have a devoted service interface and calibration software,” says Shah.
A main calibration board is used for calibration of instruments, and its integration with the software as well as the interface can be difficult
Apart from that, there could be the possibility of experiencing other minor hindrances like, “Instrument holder availability during calibration or ambient conditions necessary and so on,” adds Shah.
Equipment versus labs
The prerequisite for stable and optimum conditions calls for maintaining the equipment under very specific environments. Calibration labs come as a suitable solution to this. Necessary ambient conditions for calibrators that can be maintained only in labs ensure accuracy and longer life of the instrument. “Soaking period required by instruments before calibration, devoted apparatus and equipment required for calibration can only be found in calibration labs,” explains Shah.
Another major advantage of favouring calibration labs is the lab certification that is issued for instruments. Shah says, “This is a priority for all internal and external audits.” Krishna explains the requirement of a full pre-adjustment report on instrument performance as the need to know precisely where and how far out of specification it was before calibration. “This is a growing requirement for ISO 9000 compliance,” he adds.
However, when instruments cannot be taken out to calibration labs, because of certain limitations, the calibrators can be of a huge help. “We do not have to carry measuring instruments to calibration labs and can calibrate these using calibrators,” says Shah.
The slow wave of calibration
Overall, calibration equipment have continued to improve in performance to ensure that these are capable of calibrating test equipment. We also see that the trend of connected devices and test equipment has made its way to calibrators as well.
Additionally, if a piece of equipment is going to govern the quality of function of other devices, it has to be of optimum quality, as, Krishna adds, “measured values are the basis of decisions.”
You may also like other Test and Measurement articles.
Saurabh Durgapal is working as technology journalist at EFY
