Chauvin Arnoux CA40 [P01167501] Electromagnetic Field (EMF) Meter. Chauvin Arnoux's CA40 is an easy to use electromagnetic field meter made for the detection of electromagnetic fields from 0.1 to 200mG.  By using the CA40, it's possible to detect the presence of leaking electromagnetic radiation, then follow the increasing field values to locate the source(s) of the disturbance. The system consists of two parts; a handheld meter used for displaying the amount of radiation and a separate sensor equipped via a long cable to the meter. The equipped sensor - an external ambient field probe - is polarised on a single axis and is made to detect industrial current at 50/60Hz, plus associated harmonics. This electromagnetic field meter is ideal for use in a wide variety of applications, including detection of EMF on transformers, electromagnets, high-tension lines, electric ovens, cathode screens and other common equipment such as computers, fax machines and printers.