The Fluke 28 II Ex digital multimeter define a new standard for operating in harsh conditions with the features and accuracy to troubleshoot most electrical problems. Both meters have IP 67 (waterproof and dustproof) rating, MSHA approvals, extended operating temperature range of -15 degree C to + 55 degree C and 95% humidity, and a 3-meter drop. They withstand hazardous 8.000 volt spikes caused by load switching and faults on industrial circuits and complies with second edition IEC and ANSI electrical safety standards. Furthermore, the 28 II has a unique function for accurate voltage and frequency measurements on adjustable speed motor drives and other electrically noisy equipment. The new Fluke 20 series multimeters are built to work in the toughest environments.