The ELF power-frequency meter
The EMFields ELF power-frequency meter - Further Information
The EMFields ELF is our best ELF meter and has a digital readout and measures electric and magnetic fields with frequencies from 10 to 2000 Hz (±3 dB). The magnetic scale has a resolution of 0.01 microtesla (10 nanotesla) and a full scale of 19.99 microtesla. The electric scale has a resolution of 1 volt/metre and a full scale of 1999 V/m (with accuracy of ±2% ±3 digits at 50/60 Hz).
This is the meter to use for EMFs from electric power sources - overhead lines, substations, underground cables, house wiring, electrical appliances and equipment, etc. You can use it to measure the electromagnetic fields (EMFs) at home and in the workplace. It is hand-held and with it you can measure the fields at any time of the day or night. The hire meters are sent out with full instructions by Royal Mail 1st class recorded delivery. If you need to take readings urgently, perhaps there is little time before a decision about buying a property needs to be made, you can request our priority post service which means the meter is sent Special Delivery. If you place the order before 11.00 a.m, it will usually be sent the same day, and you should receive it the following day. Both Recorded and Special Deliveries are signed-for services. We can send the meter to your work address if this is more convenient for you.
At work you may be exposed to quite high levels of fields. In the office environment, there are computers, VDUs, cabling, faxes, photocopiers, printers, fans, table lamps, scanners and fluorescent lighting. Fluorescent lighting can generate very high levels of electromagnetic fields, and have been found to be responsible for occupational ill-health, frequent work absence, and for initiating electrical sensitivity, a seriously debilitating condition.
Power consumption, and the associated electromagnetic field levels, varies over time in a house. The peak periods of power demand on the circuit are likely to be between 8.00 a.m. and 9.30 a.m. and between 4.30 p.m. and 6.30 p.m. depending on the area where you live. There may be a period of high demand between 12 midnight - 8.00 a.m. if there are many people in your neighbourhood who use night storage heaters. In cold weather, field levels can be up to three times higher than in periods of warmer weather, because of the greater use of electric heating and cooking. If your power supply circuit serves shops, schools, or industry, especially if these include long days or opening times, or overnight working, it may significantly change power demand and field levels both inside and outside the house.
The fields in your garden may vary due to the presence of overhead or underground cables, substations or transformers.
Differences between the EMFields ELF and the ELF3030B meter
The ELF PF4 and the Gigahertz 3030B can give different electric field readings, with the 3030B often presenting a figure around twice that of the PF4. This is not a calibration error or inaccuracy, but is instead due to a different method of assessing the electric field. The 3030B is designed and calibrated to measure the electric field at the end of the instrument in direct relation to ground. This is why they recommend using the earthing lead they provide with the instrument, and using this lead is required for your measurement of the electric field relative to ground to be accurate with respect to the ground. This will always give a considerably higher measurement reading, unless you are standing with bare feet on an earthed conductive surface.
The ELF PF4 is designed to measure the electric field level which your body is experiencing, so it is relative to your body, instead of to ground. This was intentional as we believe that it is the actual fields that your body is experiencing that matters most.
An example of the difference is that birds can perch on very high-voltage powerlines without being injured. This is because they only have a low number of volts actually across their body. However, they are technically sitting at hundreds of thousands of volts relative to the Earth. In this situation, the 3030B would read hundreds of thousands of volts (way over scale and it would be permanently damaged), but the PF4 would read only a few hundred or less.
The 3030B can be used like the PF4 (without the earthing lead), but if used this way it still gives higher readings. If held in the same manner as the PF4 (at the bottom, around the battery compartment) then it reads roughly twice as high as the ELF PF4.
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