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The following information may help you get your PPM Magnetometer operational.
1. After I constructed my first magnetometer, I could not hear the precession signal. I was working indoors in my lab and I knew the magnetometer had been constructed OK because it was so sensitive I could hear it picking up the ticking of my analog quartz wristwatch that I was wearing on my arm. I spent months at my workbench with no success. Someone suggested that the magnetometer was so sensitive that appliances in the building were causing major magnetic anomalies sending the magnetometer off scale. I took the magnetometer outside and away from the building and tried it. I was thrilled because for the first time I could hear the precession tone loud and clear.
2. Don't forget, the sensors must be oriented east and west during polarization. This polarizes the sensor protons at right angles to the earth’s magnetic field. When the the polarizing current stops, the protons swing a full 90 degrees and precess into the earths magnetic field and induce the maximum precession signal voltage into the sensor coils.
3. You may wish to experiment with other proton rich fluids or toroidal sensors. Do not introduce "Unknowns" into this project until you get the original mag working. Build the magnetometer per the plans, get it working, then you may wish to try substituting components.
4. To tune the sensors, set your audio signal generator to 2025 Hz . Connect the audio signal generator output across the two series connected sensors through a series resistor like 100K and measure the voltage across the sensors using an AC Voltmeter. (Adjust audio signal generator output level as necessary to obtain a low voltage reading)
Connect a capacitance decade box across the two sensors where the meter is connected.
Using the capacitor decade box, adjust the capacitance to peak the voltage across the sensors. This point is obtained when the sensors and capacitors resonate at the precession frequency.
The capacitance read on the box is the value required to tune the sensors (C100).
This is a standard procedure for tuning a parallel resonant tank circuit using a constant current source.
You may temporarily space the sensors to about 24” for testing purposes. They will be easier to handle. This close spacing reduces the magnetometer sensitivity but is OK for testing purposes. When one sensor is rotated 180 degrees with respect to the other sensor, the background noise will either increase of decrease. Use the position that produces the lowest noise level. This assures that you are in differential mode and that the magnetometer will function as a gradiometer. When your testing is completed you may space the sensors at 6 feet to 9 feet apart for higher sensitivity.
I can Email a rather large WAV file of "The sounds of the Proton Precession Magnetometer" to you. Just request by Email to [email protected].
1. After I constructed my first magnetometer, I could not hear the precession signal. I was working indoors in my lab and I knew the magnetometer had been constructed OK because it was so sensitive I could hear it picking up the ticking of my analog quartz wristwatch that I was wearing on my arm. I spent months at my workbench with no success. Someone suggested that the magnetometer was so sensitive that appliances in the building were causing major magnetic anomalies sending the magnetometer off scale. I took the magnetometer outside and away from the building and tried it. I was thrilled because for the first time I could hear the precession tone loud and clear.
2. Don't forget, the sensors must be oriented east and west during polarization. This polarizes the sensor protons at right angles to the earth’s magnetic field. When the the polarizing current stops, the protons swing a full 90 degrees and precess into the earths magnetic field and induce the maximum precession signal voltage into the sensor coils.
3. You may wish to experiment with other proton rich fluids or toroidal sensors. Do not introduce "Unknowns" into this project until you get the original mag working. Build the magnetometer per the plans, get it working, then you may wish to try substituting components.
4. To tune the sensors, set your audio signal generator to 2025 Hz . Connect the audio signal generator output across the two series connected sensors through a series resistor like 100K and measure the voltage across the sensors using an AC Voltmeter. (Adjust audio signal generator output level as necessary to obtain a low voltage reading)
Connect a capacitance decade box across the two sensors where the meter is connected.
Using the capacitor decade box, adjust the capacitance to peak the voltage across the sensors. This point is obtained when the sensors and capacitors resonate at the precession frequency.
The capacitance read on the box is the value required to tune the sensors (C100).
This is a standard procedure for tuning a parallel resonant tank circuit using a constant current source.
You may temporarily space the sensors to about 24” for testing purposes. They will be easier to handle. This close spacing reduces the magnetometer sensitivity but is OK for testing purposes. When one sensor is rotated 180 degrees with respect to the other sensor, the background noise will either increase of decrease. Use the position that produces the lowest noise level. This assures that you are in differential mode and that the magnetometer will function as a gradiometer. When your testing is completed you may space the sensors at 6 feet to 9 feet apart for higher sensitivity.
I can Email a rather large WAV file of "The sounds of the Proton Precession Magnetometer" to you. Just request by Email to [email protected].