Basic measuring functions: It can measure insulation resistance IR, and some instruments can also measure absorption ratio DAR, polarization index PI, dielectric discharge rate DD, step voltage SV, etc. For example, the insulation resistance tester HZ-2770 has a variety of measuring functions, and also supports two DAR absorption ratio calculation modes: R600s/R30s and R600s/R15s.

Data processing functions: Some instruments have data storage and printing functions, which can preserve measurement data for a long time. Some of them can also export data to a computer through interfaces such as USB, LAN, etc. For example, the TOS9301 insulation resistance tester from菊水 can store 100 sets of test results and supports USB/PC export.

Other functions: equipped with automatic discharge, sample breakdown protection, arc mode and other functions, such as HZ-2770 insulation resistance tester has a separate discharge circuit, which can quickly discharge the sample after the test is completed, and can also continue to work in the breakdown arc mode, which is convenient to locate the position of the insulation weak point.