HMI Systems produce a range of professional quality compact triaxial magnetic field meters for the measurement of magnetic fields produced by alternating current (AC) in circuits delivering electric power.
The HMI -1 EMF meter is a small, 120mm x 60mm x 25mm, handheld triaxial instrument for measuring power frequency magnetic fields. The HMI -1 EMF meter has a number of advanced features: it performs a harmonic analysis on the magnetic field and also collects statistical information on the field values measured while the EMF meter is switched on.
The HMI -1 EMF meter measures the magnetic field in three axes and automatically calculates the resultant field. The instrument is auto-ranging and can measure resultant fields up to 6000mG. True RMS quantities are used for all readings. In addition to broadband measurements, the HMI -1 EMF meter calculates fundamental power frequency and third harmonic components of the field, as well as the totality of fundamental and power frequency harmonics. The displayed reading updates once per second.
The HMI -1 EMF meter uses a 16X2 character LCD alphanumeric display. A push button switch on the front of the instrument cycles the display through six screens. This allows a great deal of information to be displayed to the user.
While the HMI -1 EMF meter is primarily a survey meter and has no external connections, it collects statistics on the field while switched on. The percentage distribution of the broadband resultant RMS field readings in eight "bins", (0 - 4 mG, 4 - 10, 10 - 30, 30 -100, 100 - 300, 300 -1000, 1000 - 3000, 3000 - 6000), is collected and displayed on one screen. Also minimum, maximum, average and standard deviation values of the field during the time the meter is switched on are recorded. This statistical data is retained under low battery voltage condition.
The HMI -1 EMF meter uses a standard 9 volt alkaline battery and the average current drain is less than 10 mA.