Safety in Measuring Tools

Safety in Measuring Tools

Studies have shown that the networks are generally higher than the voltage they should have. In particular, temporary regime changes cause thousands of volts of voltage to be seen in the networks. By establishing a safety standard in measuring instruments by IEC, it has been tried to eliminate the dangers that may arise when using it in measuring instruments. The safety categories of the IEC 1010-1 standard are based on overvoltages. The devices within this standard are categorized according to their distance to the network and their ability to suppress energy transitions in electricity distribution systems.

Which Protection Class Should I Choose?

The safety standard in measuring instruments, formerly used as IEC 348, was replaced by the more advanced IEC 61010-1 standard in 1988. With the new standard, higher level of security applications have come. Accordingly, the safety classes are divided into 4 classes, CAT I, CAT II, CAT III and CAT IV.

Safety in Measuring Tools

Separation of CAT I, CAT II, CAT III and CAT IV safety classes

Accordingly, the closer your working area is to the source, the network, the higher the security class you should choose. You can see which class you should choose from the table below.

Safety in Measuring Tools

Descriptions of measuring instrument safety classes.


Increasingly growing networks, the increasing popularity of power electronics applications have increased the number and range of transient regime changes in the networks. The resulting jump voltages are generally the main factors in the failure of measuring instruments. You can reach the maximum jump voltage that protection classes can withstand from the table below.

Safety in Measuring Tools

Protection classes according to jump voltages

A frequently asked question is the dilemma of a CAT III 1000 V meter and a CAT IV 600 V meter. Here, the distance of the location to be measured from the source should be based on. Since the short circuit current will increase as you approach the source, the short circuit current that may occur must be absolutely taken into consideration.

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