?ETS-Lindgren's Model HI-1801 Microwave Oven Survey Meter is a durable, compact and portable instrument for accurately measuring microwave oven radiation. The HI-1801 Microwave Oven Survey Meter is especially suited for appliance service applications, ideal for public health agencies and service technicians to check microwave oven radiation leakage. ?The CHECK feature on the HI-1801 allows the user to determine that the microwave oven and meter are both operating properly.