Mollensoft Labs         
Specializing In Educational & Scientific Freeware as well as Intra-net Specific Servers/Clients, Custom Sensors and processing tools for Scientists (or Anyone's)  Use in the Lab.   Programming Languages: Perl & Visual Basic & C#


Magnetic Field Sensor


Fluxgate Mag Compass 

SqlFar Archive Tool

Reachbility King

 Intra-Net Email Server

 Anti-Spam Protocol
 Hall Effect Mag Sensor 


Magnetic Field Sensor Science Experiment: This is an ongoing development project using FGM-3 magnetic field sensor.   Below is the (ongoing) resultant data including pictures of the setup and description of the implementation.

The design uses an SCL field sensor type FGM-3 (From Fat Quarters Software). The signal from this unit is fed into the integrated circuit which performs all the functions required to the level of providing a digital output on eight parallel lines which mirrors the tiny field fluctuations. This output is then fed directly to the input port of a serial-to-ether server which forwards the data over wired (CAT-5) Ethernet to a computer for data analysis.

To remotely deploy this sensor, I am using the SITE Player Telnet Serial-to-Ether converter/controller from

The Sensor (FGM-3) is housed inside a small section of 4" PVC tube that is capped on both ends with PVC ends. 


Here is the container with the PVC Cap About to be placed onto it.. note the wires exfiltrate the container thru a small hole drilled in the top of the upper PVC Cap.... the wires are sealed on both sides with a rubber grommet and silicon sealant to ensure the inside of the container remains Waterproof.

In the future, I hope to employ the Zigbee type "Xbee" wireless network transceiver set so I can get rid of the Cat-5 cable (if the price of the zigbee technology comes down abit).

Here is a picture of the Temperature/Light Sensor Suite and it's connection to the SitePlayer which converts the Serial output from the Basic Stamp to ethernet for the run over CAT5 cable into our Lab. A second SitePlayer Converts the Data back into serial as it is fed into the logging computer's Serial port.  The use of SitePlayer enables the use of (available) long data runs using them as serial to ethernet bridges. Notice the Temperatureand light sensors are extended 20" on wires from the basic stamp and the basic stamp's power supply is provided by a 9V adapter piggy backed off the site-player's power supply (not a 9v battery) near the sensor array.   

Temperature and Light Readings are taken at the same time as the magnetic readings enabling analysis of the magnetic data to be correlated with the Temperature and light intensity readings.

The PC Board (Below) is connected to the FGM-3 Sensor and enables users to specify 1 of 4 sensativity levels (switch) as well as a sensor reset button which I've noticed comes in quite handy. The Board is mounted into a standard Plastic Enclosure that is near a "Wall Wart" Double Regulated Powersupply. 

The Sensor's Rectangular Signal is fed into the PC Board which performs all the functions required to the level of providing a digital output on eight parallel lines which mirrors the tiny field fluctuations.

This output can be fed directly to the input port of a computer... the PCB's IC converts the period variations to an eight bit digital output, (after amplification and comparison to a chosen zero reference).

The sensors will be buried underground 14" below the surface of my back yard to help stabilize the units Temperature as variances in the FGM-3 Sensor's operational Temperature will cause the readings to change. Therefore a Temperature/Light:Magnetic Flux reading correlation must be implemented.

Much More Pictures/data to come!



Copyright © 2000-2008 [Mark Mollenkopf]