Safety requirement EN ⚫ Class II refers to measurements taken on a circuit directly connected to low- voltage instruments. For example, measurements made on household appliances, portable tools, and similar equipment. ⚫ Class III refers to measurements taken on construction equipment. For example, measurements made on switchboards, circuit breakers, circuits (including cables, busbars, junction boxes, switches, sockets) in fixed equipment, as well as equipment for industrial use and certain other equipment (for example, fixed motors permanently connected to fixed instruments). ⚫ Class IV refers to measurements taken at the source of low-voltage equipment.
For example, measurements made on electricity meters, primary overcurrent protection equipment, and pulse control units. 1.4 Ventilation Requirement To ensure sufficient ventilation, when using the instrument in a workbench or rack, please ensure that there is a gap of at least 10 centimeters on both sides, above, and behind it. Note: Poor ventilation can cause an increase in instrument temperature, leading to instrument damage. Good ventilation should be maintained during use, and ventilation openings should be regularly checked. HBT3000 series user manual Copyright © Qingdao Hantek Electronic Co., LTD 4