This is an EMF detector, it uses the electrodes of the Photocell as the indoor aerial to detect alternating currents. The circuit uses the decade counter IC 4017. The circuit should respond to any alternating signal.
eBay
3in1 Electric Field Magnetic Field RF Radiation Detector Electromagnetic Radiation Tester EMF Meter
Aliexpress UK
New but was taken out of the box. Sat in drawer unused.
eBay
FNIRSI ERD-10 4-IN-1 Electromagnetic Radiation Detector Electric & Magnetic Field Strength RF Power
Aliexpress UK
The circuit uses the decade counter IC 4017. The circuit should respond to any alternating signal. Use as it is or ideal for mounting in your own box. This is for the complete assembled unit including the 6V battery box ,(batteries not included) and the photocell tube valve.
eBay
ANENG GN902 Electromagnetic Radiation Detector Temperature Tester Radiation Field Tester Portable
Aliexpress UK
The 1st Light detects a Normal EMF field, what is always around us.The range is between 0 to 1.5 mG. The 2nd Light (GREEN) detects a Low Level EMF,which range is between 1.5 to 2.5 mG. The 3rd Light (YELLOW) detects a Mid Level EMF in the range between 2.5 to 10 mG.
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Battery Powered 5 LED Indicators Electromagnetic Field Radiation Detector EMF Instrument Portable
Aliexpress UK
1 x EMF Magnetic Field Detector. Size: 14.3cm x 5.2cm x 2.5cm (L W H). Detection Range: 0 to 20+ milliGauss.
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Electric Field EMF Meter Detector Handheld Portable Counter Radiation Dosimeter Monitor Tester
Aliexpress UK
It is used to test and learn electromagnetic radiation situation indoor and outdoor. 1 Electromagnetic Radiation Detector. Data locking, one-key lock of the radiation value. Alarm Threshold: Electric: 40V/m; Magnetic: 0.4μT.
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MC-38 Wired Door Window Sensor Detector Magnetic Switch Normally Closed or Normally Open NC/NO for
Aliexpress UK
The electromagnetic radiation tester successfully tests the compatibility of electric field radiation and magnetic field radiation, and achieves the best test results. Data hold and clear LCD display, one-key can lock the radiation value and easily read the value.
eBay
MC-38 Wired Door Window Sensor Detector Magnetic Switch Normally Closed or Normally Open NC/NO for
Aliexpress UK
The 1st Light detects a Normal EMF field, what is always around us.The range is between 0 to 1.5 mG. The 2nd Light (GREEN) detects a Low Level EMF,which range is between 1.5 to 2.5 mG. The 3rd Light (YELLOW) detects a Mid Level EMF in the range between 2.5 to 10 mG.
eBay
MS-6500B Kristallmatte Far Infrared Energy Heat Crystal Mat Pulsating Magnetic Field Therapy PEMF
Aliexpress UK