Instruction Manual

For the

By Quantro Sensing. www.quantrosensing.com

P.O. Box 175, Grant FL. 32949

321 412 1160.         2007. Version 1.0

Section 1. Assembling the sensor. Page 3 .

Section 2. Filling the sensor with charcoal barbecue lighter fluid. Page 5.

Section 3. Setting the tuning for your area of search. Page 7.

Section 4. First use instruction. Page 11.

Section 5. Usage and general search tips. Page 13.

Section 6. Tone audio indicator. Page 21.

Section 7. Care and warnings concerning the proper use of this instrument.

NOTE: Never turn on and run the Discovery without fluid in the sensor. You will not receive a signal and the sensor may overheat and destroy the sensor!

Discovery is warranted for a two year time period from date of sale. We will repair or replace at our sole discretion any defects in the product that have not been caused by mistreatment, abuse or accident.

Discovery is a high quality instrument and if cared for properly it will run for many years.

Discovery is a one gamma resolution proton type absolute magnetic field readout magnetometer. Each sampling of the earth’s total magnetic field is computed and displayed as a numeric readout in units of 5 numbers of the gamma value. The gamma unit of display is the worldwide scientific standard.

The proton sensor is Omni directional. Meaning that it senses ferrous metal in a ball type area with the sensor in the middle of the ball equally in all directions. It is noise canceling, has a high output.

Cycle Time, is user selected at 1 1/2, 3 and 6 seconds per new reading.

Tone Signal Audio Output is built in and changes up and down in tone following the gamma readout. It can also be turned off.

Alarm is user selectable to sound off with a change in gamma value of 3, 6 and 9 gamma to indicate a possible target or it can be turned off.

Battery Condition Indicator is a light that shows the battery condition in three states as full, half and empty.

RS232 Output is a digital ASCII signal of the gamma reading that is outputted after each new reading at 9600 baud speed for use with a computer GPS software display and logging program. A low cost Magnetic search computer program is available at QuantroSensing.com

Control box is plastic and aluminum, 8 inches wide x 2 1/2 inches high and 7 inches deep. Weight is 2 LBS.

Power required is 12 volts at 2 amp hr minimum. Power used is 2 amp maximum.

Cable to the sensor is 100 feet long and .33 inch dia. Weight of cable is 6 lbs.

Sensor is 22 inches long and 4 inches in diameter. With fins on 26 inches long and 12 max dia. Weight is 7 lbs.

Section 1. Assembling and using the LC1 Boat towed proton magnetometer.

Please install the weighted fin down and with the index mark up or down. There are two index marks partially drilled opposite each other into the dark gray PVC end fitting that holds the fins. This will help keep the sensor in the correct position. Snug the set screw with a 1/8 inch Allen wrench. Do not over tighten or you will break the fin.

Install the fins so that the weighted fin goes on last to hold the other fin to the fish. In other words the weighted fin holds captive the first fin installed. The set screw is snugged firm against the weighted fin.

Section 2. Filling the sensor with charcoal barbecue lighter fluid.

The magnetometer sensor must be emptied of the flammable charcoal lighter fluid if it is shipped by any Common career.

UPS, FedX and the US Postal Service. This is due to shipping regulations concerning flammable fluids.

The sensor is emptied by removing the fill plug, turning it over and standing it upside down in a bucket for 5 or 10 minutes.

Charcoal lighter fluid used in the sensor is safe. Most people in this country have had experience using it at one time or another. Be safe!

You will need to buy two quarts of charcoal lighter fluid in a plastic container because it has less of a chance of having small pieces of ferrous steel from a metal container in the fluid.

Also never run the mag without fluid in the sensor because heat may melt the thin insulation on the wires which may ruin the sensor.

Remove the fill plug from the fill hole in the end of the sensor. Only use your hand when tightening this plug snug tight only. Note that this plug has an O ring on it.

Make sure that the sensor is clean, dry and free of sand, water or dirt.

A small funnel with a 1/8 inch PVC tube attached makes filling the sensor easy. Insert the end of the tube 5 inches in and start filling. This will allow air to escape between the tube and the sides of the fill hole and will allow fast filling. If you try to pour the fluid into the hole it can be done but will take much longer due to air bubbling up trying to escape the sensor. through the down stream of fluid.

You do not want anything to get into the sensor that may contaminate it and spoil the ability of it to produce the strongest possible signal. Once sand or dirt gets into the sensor it is impossible to get it out. Even a tiny amount may spoil the sensor.

Charcoal light fluid should be used but in a pinch rubbing alcohol (isopropyl alcohol) and even diesel could be used.

Carefully clean and replace the plug and hand tighten until the o-ring makes contact, then one half to three quarts turn tighter.

When properly tightened it should feel much looser to your hand than a normal metal screw would.

Section 3. Setting the tuning for your search area.

The tuning must be set to a close value by looking at the gamma chart in this manual. FIND YOUR LOCATION AND WRITE DOWN THE GAMMA VALUE close as you can decipher from the lines on the chart. Subtract 2000 gamma from the charts value.

Open the tune plug which is a 1 and ¼ inch dia black plastic cap which could be on the top or bottom on the control box. Remove the plug by pulling it out with you finger nail or sharp object.

Set the tuning for a new search area using the gamma field value from the magnetic map. This will get you close. The mag field is changing constantly. Presently the field is decreasing at a rate of 60 gamma’s a year.

Use the tuning table to find that gamma value and write down the switch settings that are next to it. These are the closed or on settings. If the table said 1,2,3 then only 1,2,3 will have their levers towards the circuit board. The unused switches will be away from the board or open position. Open meaning that the switch is not connecting the wires so the circuit is open. Or open circuit.

Take some readings in a magnetically clear area at the search area to see how close you came with the tuning. If you consistently get the same reading within a gamma or two write the reading down because it is the absolute field value at that spot.

If the gamma field reading is more than 150 gammas from the value you used to set the mag then go back to the tune chart and find the correct value and reset the switches to get the best performance.

You should try one setting above and below the chart setting. Use the most stable of the three. Even 1% components can drift.

The tuning chart and magnetic map will always be posted at the Quantro Sensing web site so that you can get the info from any library that has the internet.

NOTE: FIND YOU’RE VALUE AND THEN SUBTRACT 2000 GAMMAS FROM THE SHOWN VALUE. THEN USE THAT NUMBER IN THE TUNING LOOKUP CHART FOR THIS CHART.

GO TO WWW.GEOMAG.USGS.GOV FOR REAL TIME MAGNETIC READINGS. USE THE ( F ) COMPONENT THAT IS TOTAL PROTON FIELD.

This is a view of the mag tuning switch. It is ten switches built into one mini housing. It is called a ten position micro dip switch. Note how the switches are labeled 1 through 10. (Note some magnetometers have a 12 position dip switch) Also note that switch 1 is left and 10 or 12 are closest to the edge of the board nearest to the tuning plug hole.

This is set at 2,6,7,9 which are for 48,000 gammas.

Section 4. First Use Instructions.

Plug the sensor cable into the back of the control box and twist the locking ring nut sung tight only. (Hand tight).

You should use a car battery that is separate from the boat system for a clean power supply to the magnetometer to avoid possible interference from the boats charging system, blowers and radios ect. A fully charged car battery will run the magnetometer for two or three 8 hour days of searching. NOTE THAT THE BLACK WIRE IS POSITIVE +. AND THE WHITE WIRE IS NEGATIVE -. Do not reverse these or you will damage the electronics.

If you have a large boat (30+ feet in length with twin engines) or a steel boat you will want to use all 100 feet of cable to get the sensor away from the magnetic influence of the boat and engines.

If you are using a fiberglass boat 16 to 24 feet in length then you may only need to use 50 feet of cable out to avoid the influence of the steel in the engine and outdrive. Some experimenting may be needed.

Set the switches to cycle a new reading every 1.5 seconds turn the tone switch on and turn the power switch to the first on position which is on but the alarm feature is off. MAKE SURE THE BLACK WIRE IS TO THE + TERMINAL ON THE BATTERY AND THAT THE WHITE WIRE IS TO THE – TERMINAL OF THE BATTERY BEFORE YOU TURN THAT POWER SWITCH ON.

The gamma readout will start displaying new reads every second or so and the piezo will start growing with the magnetic field changes.

You should tow at a slow walking speed of three MPH at first to get the hang of how the sensor tows. There is no need in most searches’ to get the sensor very close to the bottom. Depending on what you are searching for 20 feet off the bottom should be fine. This means that in water that is only 10 to 25 feet deep towing with the sensor on the surface is fine. I you want to get the sensor down deeper then you could add lead diver weights into the nose of the fish and or tow slower.

Towing slower allows the fish to go deeper and towing faster raises the fish higher due to the up lifting force of the cable cutting through the water at a lifting angle. Also if your speed remains the same and you turn the boat sharply the fish will dive deeper due to it slowing down. So in a sharp turn you may need to speed the boat up some. You could turn on the alarm feature and get familiar with how it works.

Use of a proton magnetometer is nothing like using a metal detector.

With the Discovery Proton Magnetometer the sensor senses the same in all directions. Up down, left right, forward and backward and every other direction in between.

You should think of it like the sensor is in the center of a large ball and it sense the gamma field at the spot where it is at equally in all directions. Actually it is sensing the earth’s magnetic field right at the sensor but possible targets are distorting the nature earth’s field and it is sensing that distortion.

It is beyond the scope of this manual to try to fully describe the proper use of a magnetometer.

We strongly urge you to become an expert in the field of magnetic search. There is no other type of remote sensing instrument in the world that comes even close to the ability of a properly used magnetometer to search for a target with 100% results.

If you really did your home work you will be able to search for any size target with 100% confidence of either finding it or knowing for sure that is or is not where you searched.

This can never be said for searches using sonar, all metal type detectors, or pipe finders. At the end of this chapter we will list some recommended reading and other information sources on magnetometer search.

This is now the time to tell you the single most important fact of magnetic search. Please remember this point.

Ferrous steel targets simply distort the natural earth’s magnetic field where they lay. They add to or subtract from the field that you are reading by distortion. They distort the field by pushing it closer together at one spot creating a higher reading.

Or pull away some of the natural field strength from other spots near the target creating a lower gamma reading at that spot than normal.

So really you are looking for the disturbance in the natural field created by the target when searching for a ferrous object.

An easy way to picture this is to remove the blankets from your bed so that you are looking at a tight bed sheet.

This represents the natural earth’s field without unnatural ferrous steel targets distorting the lines of flux.

Now place a ten pound scuba weight on the sheet (we will pretend that it is ferrous steel) and you will start to picture how targets only distort the natural field value.

Now the sheet is not even all over and some sides of the target make the sheet slope steeper than other sides of the target. So there are some areas around the target where the sheet has less of a slope or change in the field reading than other areas near the target.

Now notice how far from the weight the sheet is affected. This may be one foot, so you could envision that this represents how far away from the target you might sense it or sense the change from the normal field the target made.

If you were to place a heavier target on the bed you would see that the sheet is affected farther away from this larger target. This may be two feet or so away from the weight that the sheet is no longer flat.

This would mean that since the heavier target affected or distorted the field farther out you could assume that you could sense this change from farther away.

Here is a graph that will give you a general idea of how far away you can sense a ferrous target of a given weight.

The chart has two examples already drawn on it. The first is a 1 LB steel target and we want to find out how close we have to pass the sensor to it to get a strong reading of a 5 gamma change from the natural field reading.

We know two of the three variables, one is the weight and the other is the strong reading that we want to see. So we start at the 5 gamma point on the chart and move straight over to the known weight of 1 lb. Now we drop straight down from that point and we have answered the question. Its 6` that the sensor must be within from the target to see a 5 gamma change.

For the second example we will show you another use of this chart.

PINPOINTING

Let’s say that we were searching and we ran across a seemingly large buried target. We wondered what it could possible be!

We have some paper along and we noted a 25 gamma increase in the natural field reading when we were about 35` from the center of the target on the east side and the west side.

So when driving east or west through the target area to pinpoint it the gamma reading was 25 gamma higher on both the east and west side of the target at 35 feet away from the center reading over the object.

So looking at the chart we again know two of the three parts to the problem. We draw a line straight over from the 25 gamma value that we noted. Now we look at the bottom of the chart at the feet from the sensor scale and we find our distance of 35 feet and draw a line straight up.

We now see that the target must weight around 2,000 lbs. of ferrous steel to make that kind of a disturbance. There’s something big there. Going one step further you may want to dive down to run a coin metal detector over the target to try and determine the outline of the object if it is close enough to the surface.

It is good to practice first in a clean area without targets so that you will build confident in the Discovery’s ability to read the earth’s natural smooth magnetic field.

Next practice on a known target like a metal buoy or channel marker on a steel pole. Keep in mind that a buoy or pole of a marker may weigh something like a 500 LB steel ferrous target.

The ferrous weight of the target in pounds is the main determining factor that will set how far away you could possibly sense it. But remember that you’re really sensing the distortion that the metal creates in the normal field.

While motoring to and from the target you will see the gamma readout change. It is important to make a mental note of the clean area gamma reading or better yet write it down on a slate. You should only focus on the last 1 or 2 numbers of the readout. An example is to remember the 21 in the gamma readout of 45321 gammas.

While motoring slowly towards the buoy from 150` feet away the readout will stay the same reading after reading until you get the sensor to within 50`feet or so.

Then you will see the gamma reading rise a gamma or three from 321 to 324. Also if you have the tone on it will start to rise in pitch. Still motoring closer and the sensor is now 30 feet from the buoy you will see the gamma reading rise to 330. Motoring closer at 20 feet away it will read around 380.

While motoring away you will see the gamma reading dropping back down and the tone dropping down to the normal no target earth’s field reading that you noted earlier.

So the field may change 100 or more gammas’s if you get close to a large ferrous object.

Locating any ferrous metal target is easy and precise with a proton magnetometer. Of course you will need some practice. Search contractors, military forces and geologists world wide have done so with complete accuracy since the 1950`s. They have pinpointed where to find the wreckage, were to drill for oil and the exact location of that sub.

Simply motor slowly east or west through the general area of the target noting the highest reading and throw a buoy into the water at that spot. Your target will be very close directly to the north or south on this line.

Now motor from the south end of the target area towards the north on the line noting the highest reading throw another buoy at that spot. Your target will be right under that mark or a few feet to the south.

While searching you should investigate any area where the gamma reading rises or lowers more then 3 or 6 gammas.

Generally you would search by taking a reasonable size area maybe a ¼ mile square and motor back and forth while moving over maybe 100 feet or so for each new pass. This is done either by throwing out a lot of buoy to make the area or the easy way of using GPS. If you have a GPS set it to display thousands. Now in most areas of the USA every change in that last digit will equal about 5 or 6 feet.

So if you motor down a north south line keeping the lat number the same you are running GPS position lines.

If you do one line lets say 80*32.000 motoring to the north and then turned 90 deg to your left till the GPS reads 80*32.010 then turn 90 deg again to your left you will be heading south now down the 80*32.010 line and you will have moved over to the west 50 feet. So as you can see if you wanted to move over 500 feet on each pass if you were looking for a large target like a 60 foot long steel boat that would mean that the sensor at max could only be 250 feet away you lines would look like this.

Motoring north up the 80*32.000 line then turning 90 degs till you get to 80*32.100 spot and turning south down the 100 line. (That’s short for the line you’re now searching.)

It would take around 20 passes to cover this entire area.

In the search industry this tactic is called mowing the lawn. This proven method is used in searches with all types of remote sensing equipment. It is used for sonar search, visual search and also by our space probes to map the planet mars.

You would determine the distance to step over for the next pass by taking into consideration the weight of the target you are searching for and the distance from the object that it could be sensed in its worst possible case scenario from the sensor.

It maybe that the target is smaller that you thought. Or it may be laying at such an angle in relation to the earth’s field that it might be making a smaller disturbance in the field than it would if it were laying at any another angle. So it is best to be conservative on you line spacing.

1. The Discovery Handheld Proton Magnetometer Owners Manual. The latest updated version is at the Quantro Sensing web site. www.quantrosensing.com

2. Applications Manual for Portable Magnetometers by S. Brener. This may be available from Geometrics 395 Java Drive Sunnyvale, California 94086

3. Principles of Applied Geophysics by John Wiley and Sons, New York 1962.

Section 6. Tone audio output of the gamma reading.

The tone audio output is very useful and unlike to the Discovery line of proton magnetometers.

It frees up your concentration from having to watch the gamma number readout to see a target. With the tone option you can listen for the target and concentrate more on where you’re searching driving the boat and what is going on around you.

The piezo sounds a 200 Hz tone which sounds like a medium to low growl. This tone is updated with each new reading of the earth’s magnetic field.

If the field stays the same the tone continues to growl at the same 200 Hz tone. If the gamma reading changes higher or lower then the tone steps a small percentage up or down per gamma reading change from the last gamma reading.

So if the gamma reading changes 5 gamma higher than the last reading the tone will move up x percentage in frequency to maybe 204 Hz.

If the next reading is 20 gammas higher than the last as it would be if you’re nearing a target the tone will step up again x percentage to maybe 233 Hz.

As you move away from a target the tone would step back down to the 200 Hz tone that it had started at.

The tone sound can only step up or down in tone to follow at the most a 250 gamma change. This is because of the fact that you have to keep the step or percent of change for a single gamma or two large enough to hear the difference.

When the discovery is first turned on the tone immediately starts growling at 200 Hz. Now it will wait while growling for the second gamma up date and it will than use this gamma number as its centered 200 Hz value.

If the gamma field is slowly rising as it does towards mid day or noon the tone will also slowly rise. You can turn the power switch off and then back on to reset the tone to the new higher base gamma field reading.

Turning the power off and then back on can also be used if you are near a large target and the field has changed greatly.

Remember that when you reset the tone using the power switch you must wait for the third reading before you could possibly hear a change in the tone to follow the gamma readout.

Section 7. Care and warnings concerning the proper use of this instrument.

#1. Black wire to positive + of battery and White to Negative-.

#1. Do not run the mag without fluid in the sensor. It could over heat the windings ruining the sensor. This is misuse and will not be covered under the warranty.

#2. Be careful not to yank on, step on or pinch the cables.

#3. Lay the mag on something soft to stop vibrations from damaging the unit when traveling in a boat or car.

#4. Do not allow the mag to "cook" in the hot sun. Toss a blanket over it if it must be in the sun when not in use.

#6. Try to only use sensor fluid out of a plastic container to avoid spoiling the sensor with rust or micro small ferrous steel specks that maybe in the fluid.