The Combo Tester test limits are factory-set for wrist straps at 750 kilohms to 10 megohms, and for footwear at 750 kilohms to 100 megohms.
The Combo Tester is portable and powered by a 9V battery. Optional 100-240VAC power adapters are available with a North America plug or IEC inlet.
Each Combo Tester is calibrated with accepted procedures and standards traceable to the National Institute of Standards and Technology (NIST) and includes a certificate of calibration.
Standards published by the ESD Association recommend frequent testing of operator grounding devices such as wrist straps and footwear to ensure proper electrical resistance.