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SAM-III Construction Manual

See last page for document and copyright information, File: SAM-III Magnetometer Construction.doc, Page 63

XVI.

Magnetometer Sensor Installation

Read this entire section before installing the magnetometer sensors

Orientation

Magnetic field components

It is first necessary to decide what component or components of the magnetic field are to be measured.

The SAM-III supports one, two or three sensors, so it may be setup to measure the following

combinations:

1-sensor installation,

one of the following

2-sensor installation,

one of the following

3-sensor installation

X and Y

X, Y and Z

X and Z

Y and Z

A 1-sensor installation often is setup to measure the Y-component and a 2-sensor installation is setup to

measure the X- and Y-components, but it is a matter of personal choice which components are to be

measured. It is best to stay with the three components and not use arbitrary orientations. Each sensor is

labeled in the SAM-III software for one of the three magnetic field components and arbitrary

orientations are not specifically supported.

Generally, it is the Y-component that is affected most by geomagnetic storms. The K-index reported by

professional observatories is based on the vector sum of the X- and Y-component (horizontal). For

aurora watchers and amateur radio operators that take advantage of propagation opportunities caused

by geomagnetic disturbances, variations in the Y-component are of the most value. However, the other

components also show interesting variations, especially at higher latitudes, so they should not be

discounted from consideration when you are contemplating your sensor installation. The Z-component

(vertical) normally is influenced most by induced electric currents in the Earth’s crust. These currents

could be from local sources (for example, currents due to nearby powerlines), the anomalous field

component and remnant magnetism or local ore bodies.

Transient magnetic variations are of interest to SAM-III users. These usually are broken into three basic

categories: Solar daily variations (S), lunar daily variations (L) and magnetic disturbances (D). How each

magnetic component is affected by these variations is beyond the scope of this manual. For additional

information, SAM-III users are referred to online sources. Also, SAM-III users should download and read

Geomagnetism Tutorial

from this internet address:

http://www.reeve.com/Documents/SAM/GeomagnetismTutorial.pdf

Summary of Contents for SAM-III

Page 1: ...SIMPLE AURORA MONITOR SAM III 3 Axis Geomagnetometer CONSTRUCTION MANUAL Revision history on last page ...

Page 2: ... Logic Circuits 13 VIII Install the Display Components 17 IX Install the Ribbon Cables 18 X Wire the EIA 232 Serial Port Cable 20 XI Testing and Adjusting 23 XII Load the Microprocessor Operating System Firmware 36 XIII SAM Display and Keyboard Reference Information 44 XIV Install the Controller Keyboard and LCD in the Enclosure 47 XV Magnetometer Sensor Hookup 53 XVI Magnetometer Sensor Installat...

Page 3: ...lled 16 MHz clock Data displayed on backlit 4x20 LCD STN yellow green standard Measured data transmitted over EIA 232 serial interface as ASCII text K Index available on one analog output adjustable 0 5 V or 2 5 2 5 V Real time clock with backup battery Form A relay output for K index alarm maximum contact rating 200 V dc or V ac peak 1 0 a dc or a ac peak in a combination not exceeding 20 w Opto ...

Page 4: ...n programs that were used with the SAM II can be used with the SAM III except that SAM III requires a new SAM_INI program Software setup is provided in the Software Setup Guide Building the SAM III If you build the SAM III yourself Before you start you should first read through all manual sections and then follow them in order during construction This will greatly reduce the chances of error If yo...

Page 5: ... recommended Review online sources for soldering techniques if necessary The parts required for construction are listed in a table at the beginning of each section As each component or group of components is soldered and trimmed place a checkmark in the boxes provided READ ALL NOTES AND COMMENTS that follow the parts list in each section before assembling or soldering any components To avoid the p...

Page 6: ...board and the right portion is for the main controller The PCBs have two sides solder side and silkscreen side Before placing any components carefully cut the three small bridges between the controller PCB and keyboard PCB with a fine saw such as a modeler s saw Do not attempt to break the two boards apart without cutting because the likelihood is very high the boards will be damaged After separat...

Page 7: ...he pushbutton does not shift when you tack it If it does shift simply reheat and adjust Finally solder the remaining three pads and then return to the first pad and add a little solder to complete the placement See illustration right Repeat above for each pushbutton Solder the LED with shortest lead cathode in the hole nearest to the edge of the board If the keyboard will be mounted in the optiona...

Page 8: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 6 ...

Page 9: ...apacitor electrolytic 10 µF 25 V U5 1 Voltage converter ICL7660 5 V out U2 1 Voltage Regulator 7805 TO 220 5 V 1 A 1 4 40 x 5 16 in screw washers nut U1 U3 U4 3 Voltage Regulator 78L05 TO 92 5 V 100 ma G1 1 Lithium battery 3 V 3 pin X1 1 PCB header socket 8 position X2 1 PCB header socket 10 position XP1 1 Pluggable screw terminal block 8 position XP2 1 Pluggable screw terminal block 10 position 1...

Page 10: ...the holes lined up Use 4 40 hardware supplied to mechanically secure the tab insert the screw with flat washer from the bottom of the PCB Solder the integrated circuit voltage regulators U1 U3 U4 and U5 observing their proper orientation Some builders prefer to install U5 in a dual inline DIL socket see next step If you plan to use DIL sockets with the integrated circuits install them now DIL sock...

Page 11: ...MAY SHORT OUT THE BATTERY AND DAMAGE THE PCB OR BATTERY OR BOTH Assemble the dc power cable Crimp if you have the proper tool or solder the orange and green hookup wires to the box type socket contacts right for the 3 position socket connector and inset into the 1st and 3rd position on the connector There is a small tab on the contacts that catches in the slot on one side of the connector so be su...

Page 12: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 10 ...

Page 13: ... you should allow for a margin of 1 2 Similarly the SAM III input current draw is approximately 60 100 mA fully built with sensors connected but you should allow for a margin of at least 2 DO check your ac adapter leads for polarity with a voltmeter before connection If you connect the power adapter backwards you probably will not hurt anything but of course the SAM III will not work The SAM III i...

Page 14: ...D 12 Vdc Input DC Power Input 5 V 5 V If all voltages are within the specified ranges the power supply components are working properly Remove the dc power before continuing If the voltages or load current are not within the specified ranges check for shorts solder bridges and orientation of polarity sensitive components electrolytic capacitors diodes and voltage regulator ICs Do not continue until...

Page 15: ...polarity or direction Locate the 40 pin IC socket and the two crystal oscillator capacitors C19 C20 both 22 pf Test fit the three components If the capacitors are small enough and their tops are below the IC socket web then no modifications to the socket are required Solder the IC socket in position with the small notch at the end near U6 then skip the next step If the tops of the capacitors are a...

Page 16: ...ent inductive kickback so it is polarity sensitive Place the relay on the PCB so the mark on the relay corresponds with the on the PCB illustration above the text on the relay must be on the side toward the 34 pin header The relay location is marked K1 on the PCB silkscreen but only the 1 is visible Solder ICs U6 MAX232E U7 74HCT00 U8 RTC72421 U9 74HCT00 U11 LM358N and OK1 CNY17F and transistor Q2...

Page 17: ...o a socket carefully bend the leads so they are at a right angle to the body To do this grip the IC at both ends and lay one side of the IC with the pins on a flat smooth surface Carefully rotate the body toward the pins a few degrees so the pins are uniformly bent at a right angle to the IC body Flip the IC over and repeat on the other side Double check all components for location and check polar...

Page 18: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 16 ...

Page 19: ... If not remove the two end pins of the 34 pin header so that it will fit the 16 holes in the PCB See illustration above Pull the pins from the back PCB side Place the LCD module on a soft cloth with the display facing down Insert the 34 pin header as shown so that the center polarizing slot is facing out When properly oriented the cut off pins will be in the middle of the LCD module and the row of...

Page 20: ...ductor with pin 1 on both connectors See illustrations below left 10C cable shown with red conductor at top right Connector top and front view shows position of pin 1 on 10 pin connector The first and last pins are marked on the front of the connector but the numbers cannot be seen without a magnifying glass The 34 pin connector has the same configuration Insert the cable between the cable clamp a...

Page 21: ...right information File SAM III Magnetometer Construction doc Page 19 Lay the boards as shown in the illustration below with the 34 pin and 10 pin headers facing up Carefully insert the connectors in the sockets They will fit only one way Turn the three boards over ...

Page 22: ...on JP4 1 DB 9M plug JS1 1 Socket connector housing white 3 Terminal contact spring type 1 24 AWG wire 15 cm long red 1 24 AWG wire 15 cm long black 1 24 AWG wire 15 cm long green Indicates pay attention to polarity or direction Tin the solder cups of the DB 9M connector Solder a wire to pins 2 3 and 5 on the DB 9M connector JP4 using the color code shown in the schematic below Twist the three wire...

Page 23: ...I Kit some users may prefer using this more common arrangement The drawing below shows the alternate wiring arrangement Alternate arrangement 2 This arrangement saves a little panel space and does not require cutting an odd shaped hole for a DB 9 connector Use a regular 3 5 mm stereo phone jack for the connector on the SAM III enclosure as shown in the drawing below Of course a cable with DB 9 con...

Page 24: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 22 ...

Page 25: ...nterface testing and adjustment The following sections test all functions and interfaces except the magnetometer sensors The operating system firmware SAM3_ENG HEX and sensors will be installed and tested later Connect the LCD module keyboard power connector and EIA 232 serial port connector to the SAM III PCB as shown below Do not connect anything to the Aux Controls plug X1 or Sensors plug X2 at...

Page 26: ... an ac outlet receptacle The LCD probably will not show anything at this time With no sensor connected the current draw will be around 50 mA with the LCD backlight on and around 30 mA with it off If the keyboard LED is on it will add about 10 mA load Each sensor will add around 15 mA however at this time the sensors should not be connected As already mentioned the test firmware IB3_ENG HEX is prei...

Page 27: ...the current drawn by the SAM III It should be nominal 50 mA A current draw significantly higher or lower indicates a problem with a component or the soldering Use normal troubleshooting procedures to clear the problem before going to the next test If the display works go to the next test If the display does not work do not go to the next step until the problem is corrected Test the Keyboard Press ...

Page 28: ...r to HyperTerminal if in doubt use the online Tera Term manual or search online for setup procedures For example Tera Term serial port setup information may be found at https learn sparkfun com tutorials terminal basics tera term windows DO NOT connect the SAM III serial port to the PC serial port or to a USB serial adapter until instructed to do so Setup HyperTerminal Start the HyperTerminal prog...

Page 29: ...driver properties window Download the drivers directly from the USB serial adapter chipset manufacturer s website usually Prolific or FTDI DO NOT download the drivers from any location except the manufacturer s website Additional USB serial adapter information can be found at http www reeve com Documents Articles 20Papers Reeve_USBPortMgmtGuide pdf DO NOT connect the USB serial adapter to a PC thr...

Page 30: ... HyperTerminal window as shown below If nothing happens try unplugging the USB connector of the USB serial adapter and plugging it back into the PC There is considerable variability in USB serial adapters leading to many problems with serial port testing If the test message still does not appear leave the serial port connections and HyperTerminal as they are and press the Reset pushbutton on the m...

Page 31: ...1 and the following will flash on the LCD RS 232 Test okay In HyperTerminal press the DISCONNECT icon and close the program Go to the next test Test and Set the Real Time Clock The real time clock should be set to Universal Coordinated Time UTC so that it operates on the same time scale as other geomagnetometers throughout the world In the United States first go to http nist time gov to set your P...

Page 32: ... field on right will be counting If it is counting press F1 The display will flash Test okay Now the day can be set 00 01 00 00 29 32 Set date day F1 OK F2 F3 Use the F2 or F3 function keys to scroll the day field up or down When set to the correct day press F1 The screen to set the month appears 25 01 00 00 29 49 Set date month F1 OK F2 F3 Use the F2 or F3 function keys to scroll the month field ...

Page 33: ...th power removed from the SAM III controller PCB the real time clock IC is battery powered by G1 However if you ever remove the JP2 header shorting block with no power on the SAM III the clock will have to be reset This can be done when the SAM is in operation as described in the Software Setup Guide Go to the next test Test Inputs and Outputs The SAM III input and outputs appear on the 8 position...

Page 34: ...tage to digital input Press F1 to abort The digital input test can be skipped by pressing F1 If you press F1 you should see Digital input Test aborted If the test is aborted the SAM III automatically will go to the next test To proceed with the test refer to the X1 terminal block pinout shown above Connect the lead from an isolated 12 Vdc power supply to pin 1 of X1 and the lead to Pin 2 Note 12 V...

Page 35: ...o 5 V press F3 Umax P2 P1 Pin 1 of U11 Set the multimeter to the 20 Vdc range and connect the meter negative lead to position 6 ground of X1 A Press F3 Umax Connect the meter positive lead to pin 1 of U11 LM358N op amp See illustration above Adjust P1 until the meter reads 5 00 V B Press F4 Umin Connect the meter positive lead to position 5 of X1 analog output Adjust P2 until the meter reads 0 00 ...

Page 36: ...with default parameters by pressing F1 when you see the displayed text above The default parameters include basic parameters for a single sensor K index values alarm threshold and so on These are values that SAM III will use upon power up or reset The default parameters can be changed later If you press F1 the LCD should briefly show EEPROM initialized successfully The LCD should then show Congrat...

Page 37: ...r parameters were in EEPROM will be retained Trouble Shooting If problems occur during testing double check the following Current drawn by the SAM With no sensors connected the current draw is approximately 30 mA with the LCD backlight off and 50 mA with the backlight on Each sensor adds about 5 10 mA to the load current Resistors are correct values and in their correct locations Diodes correctly ...

Page 38: ...ader firmware already installed on the PIC Remember this loader only supports COM1 through COM6 If you have a USB serial interface adapter it must be configured for one of these ports Caution Not all USB Serial Adapters are the same Some adapters may work fine on the serial port test in Sect XI but will not work with PIC_downloader It has been found that at least one adapter performs so poorly tha...

Page 39: ...me Even if you do not plan to use the temperature sensor there is no harm in loading this firmware The application program SAM_VIEW will automatically detect whether or not temperature data is in the SAM III data stream If you load SAM3_ENG HEX and later decide to use the temperature sensor you can easily replace it with SAM3T_ENG HEX at that time When all parameters are set refer to the screensho...

Page 40: ...uld look like this line 4 initially will be blank but will appear after a moment X _ _ _ _ _ _ _ _ _ _ _ Y _ _ _ _ _ _ _ _ _ _ _ Z _ _ _ _ _ _ _ _ _ _ _ K 0 0 D 0nT 21 42 The display indicates blank magnetic induction values Actual values will not be displayed until sensors are connected The next section describes the display layout for reference purposes If you run HyperTerminal and connect to th...

Page 41: ...cribes how to hook up and install the sensor Troubleshooting the Serial Port If you encounter these dialog boxes when using PIC downloader there was a communication problem with the serial port Sometimes this can be resolved by unplugging and then plugging the USB connector on the USB serial adapter If that does not work use PortMon to analyze the serial connection see appendix See also oscillosco...

Page 42: ...proximately 7 Vdc PC SAM III measured at Pin 2 of JP1 after pressing RESET and while receiving IB3_ENG HEX from PIC downloader Image F0001TEK PC SAM III measured at Pin 2 of JP1 after pressing RESET and while receiving IB3_ENG HEX from PIC downloader Image F0002TEK different timebase than F0001TEK SAM III PC measured at Pin 3 of JP1 after pressing RESET and while downloading IB3_ENG HEX from PIC d...

Page 43: ...ENG HEX from PIC downloader Image F0004TEK different timebase than F0003TEK SAM III PC measured at Pin 3 of JP1 while sending RS232 text to HyperTerminal Image F0005TEK PC SAM III measured at Pin 2 of JP1 while sending RS232 text to HyperTerminal Approximately 9 Vdc PC SAM III measured at Pin 2 of JP1 while waiting to press RESET to download SAM3_ENG HEX from PIC downloader Image F0006TEK ...

Page 44: ...ESET to download SAM3_ENG HEX Approximately 7 Vdc PC SAM III measured at Pin 2 of JP1 while receiving SAM3_ENG HEX in progress from PIC downloader Image F0007TEK SAM III PC measured at Pin 3 of JP1 while sending sensor data text to HyperTerminal Image F0008TEK SAM III PC measured at Pin 3 of JP1 while sending sensor data text to HyperTerminal Image F0009TEK different timebase than F0008TEK ...

Page 45: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 43 ...

Page 46: ... indicator symbols are Quiet magnetic field 20 minute variation K2 Moderate field variations or for falling or rising 20 minute variations K4 Strong variations ALARM 20 minute variations K4 If an alarm is triggered it will reset after 20 minutes unless the condition that caused the alarm continues to be in effect Line 4 Normal operation Current period K index previous period K index and magnetic f...

Page 47: ...he microprocessor EEPROM for standalone operation using SAM3_INI and again in SAM_VIEW for logging operation with a PC See the SAM III Software Setup Guide for details on using SAM3_INI and SAM_VIEW Time HR MM The time field is self explanatory Calibration mode When a sensor is connected and function key F2 is pressed the LCD changes to show the measured magnetic induction value and sensor frequen...

Page 48: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 46 F1 F2 F3 F4 ...

Page 49: ...threading screw 4 4 x 1 2 in self threading screw Keyboard PCB mounting hardware consisting of 2 4 x 0 062 in nylon washer 2 3 x 1 2 in self threading screw 2 4 x 1 2 in self threading screw Controller PCB mounting hardware consisting of 1 4 40 x 3 8 in nylon hex standoff 1 4 40 nylon hex nut 1 4 40 x 5 16 in pan head screw 2 4 x 1 2 in self threading screw 3 4 x 0 062 in nylon washer 2 4 x 3 16 i...

Page 50: ... step drills work well Controller PCB The controller PCB is mounted in the base section with the pluggable terminal blocks facing the back away from you as you look at the enclosure The controller PCB requires two spacers one standoff and three thick nylon washers as shown in the drawings below The standoff is 3 8 in long nylon hex standoff with a 4 40 threaded stud at one end The stud is inserted...

Page 51: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 49 100 mm 89 mm ...

Page 52: ...to an oblong shape Mount the serial port connector with 4 40 hex jackscrew hardware supplied with optional enclosure Rear of enclosure with removable back plate viewed from outside NOT full size Dimensions shown are approximate and should be verified before cutting holes 30 mm 44 00 Keyboard The enclosure top section has two built in molded standoffs for the keyboard just below the display window ...

Page 53: ...he keyboard is mounted in the top section fixed window area below the display cutout The drawing below is viewed from outside of the enclosure Use a step drill or brad point drill to cut the larger holes after pilot drilling Not shown are the two mounting holes at the ends of the keyboard which correspond to the molded standoffs in the enclosure top section If these are the only mounting holes use...

Page 54: ...ews Before mounting the LCD pre thread the standoffs with the supplied screws turn very slowly so you do not split the openings Before mounting the LCD remove the protective film cover from the glass display Also peel the protective cover from the transparent window supplied with the enclosure and snap it into position in the window opening A keyboard label image is provided on the supplied CD Pri...

Page 55: ...or indicates pin designations Note that the sensors are potted into a plastic tube Some shrinkage may take place during the curing operation or from temperature cycling creating what appears to be an air bubble under the clear plastic tube This is cosmetic and does not affect sensor operation or performance Required parts for each equipped sensor Parts list ID Qty Description 1 Magnetometer sensor...

Page 56: ...it is unlikely you can fold the fingers enough to make them fit the header connector You will need to fold the conductor crimp with a pair of miniature pliers Do this very carefully to avoid damaging the contact Apply a very small amount of solder if you apply too much solder it will wick up into the socket Before inserting the single inline SIL header onto the sensor pins put a small amount of di...

Page 57: ...meter Construction doc Page 55 Note Crosstalk interference is likely when two or more sensors use the same cable This is discussed later under Mutual Interference X Sensor 5 Vdc X X2 3 Signal X X2 2 Ground X X2 1 5 Vdc Z X2 9 Signal Z X2 8 Ground Z X2 7 5 Vdc Y X2 6 Signal Y X2 5 Ground Y X2 4 Z Sensor ...

Page 58: ...ic Capacitor Sensor output Ground 5 V power 10 μF 25 v Tantalum Capacitor Note 6 SAM X Sensor 3 position terminal strip top view 4 pin sensor connector housing Note 3 Non ferromagnetic fastener 100 nF 25 v Ceramic Capacitor Sensor output Ground 5 V power Shield or shield drain wire Note 4 Apply a light coat of dielectric grease to pins Apply a light coat of dielectric grease to pins 22 or 24 AWG i...

Page 59: ...he In and Out pin locations these are the two outer pins as shown below This modification applies 12 V dc to positions 3 6 and 9 of the pluggable terminal block X2 With this modification it is imperative that a 5 V voltage regulator be installed with each sensor to provide 5 V dc for sensor operation applying more than 5 V to the sensor will damage it The wiring diagram for a remote voltage regula...

Page 60: ...sary to share the voltage or ground leads since the Cat5 cable has only 8 conductors The conductor gauge for short runs should be 24 AWG 0 5 mm or larger Longer runs should use 22 AWG 0 64 mm or larger Where outdoor cable is exposed to the weather it should be waterproof cable suitable for direct buried applications for example waterproof shielded twisted pair telecommunications drop wire type DBW...

Page 61: ...most alignments with respect to the Earth s field the two sensor frequencies are quite different and the pulling effect disappears However when their alignment with the Earth s field brings them both to nearly the same frequency the frequency pulling effect is strong Crosstalk When the signal outputs from two or three sensors are carried in the same cable from the magnetometer sensor location to t...

Page 62: ... Here are some mitigation techniques that may help reduce faulty operation due to interference 1 Different configurations of sensor cable shield bonding and grounding bond to Earth at one or both ends mid point bond to Earth 2 Burial of sensor cable 3 Low pass filter on the signal lead the low pass filter should have a cutoff frequency of 1 2 MHz 4 Single ended to differential transceiver on senso...

Page 63: ... 000 nT 0 Hz If one or two sensors are connected only those fields will show magnetic induction and frequency The fields for sensors that are not connected will show 82 000 nT 0 Hz Press F2 to exit Calibration mode X 24324nT 46847Hz Y 8013nT 55531Hz Z 10013nT 45745Hz If a frequency counter is connected to the output of each sensor the counter should show a frequency close to the frequency on the S...

Page 64: ...malfunctioning sensor or SAM III controller problem Any tiny movement of the sensor or movement of metallic objects in the vicinity of the sensor will affect its output When viewed on an oscilloscope these output variations are manifested as rapid and erratic changes in the measured pulse period Users wishing to perform more detailed tests or calibrations will need to build a Helmhotz coil or a si...

Page 65: ...is affected most by geomagnetic storms The K index reported by professional observatories is based on the vector sum of the X and Y component horizontal For aurora watchers and amateur radio operators that take advantage of propagation opportunities caused by geomagnetic disturbances variations in the Y component are of the most value However the other components also show interesting variations e...

Page 66: ...l axis does not matter Once its longitudinal axis is pointed properly the body can be rotated and it will not change the measurements Coordinate Systems One of three coordinate systems is used in professional observatories two based on geographic coordinates and one on geomagnetic coordinates Geographic coordinates North X East Y Vertical down Z Geographic coordinates Horizontal intensity H Declin...

Page 67: ...epth by making assumptions about the soil thermal characteristics Of course these assumptions are made at the expense of accuracy but they provide a good starting point Burial depth calculations are described in Burial Depth of SAM III Magnetometer Sensors When the sensors are buried in soil their outputs will drift upwards as they become accustomed to the cooler environment It may take more than ...

Page 68: ...including automobiles trucks and trains moving in the area ferromagnetic tools brought nearby and other manmade magnetic disturbances Any movement of the sensor or movement of ferromagnetic materials in its vicinity will cause a variation in the magnetic field measurements Therefore after any movement it usually is necessary to re zero the SAM processor by pressing the F3 function key Reset Altern...

Page 69: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 67 Buried Sensor Fixture Single sensor installation Typical ...

Page 70: ...nstruction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 68 Buried Sensor Fixture Three sensor installation Typical all components in USA trade sizes ...

Page 71: ...he magnetometer sensors are remotely located which will be the case in almost all applications The SAM III hardware and application software do not use or display the temperature data the SAM III reads the temperature from the DS18B20 and sends it along with magnetometer sensor induction values in the data stream for later access by the user The temperature sensor generally would be located with t...

Page 72: ...mn to the right of the Z sensor data values The temperature should be shown See example below Gaps in the temperature data are normal DD MM YY HH MM SS X DDDD Y DDDDD Z DDDDD TT T 28 07 10 22 13 58 X 6809 Y 44871 Z 7992 22 8 28 07 10 22 14 00 X 6809 Y 44871 Z 7992 22 8 28 07 10 22 14 02 X 6809 Y 44871 Z 7992 22 8 28 07 10 22 14 04 X 6809 Y 44871 Z 7992 28 07 10 22 14 06 X 6809 Y 44871 Z 7992 22 8 ...

Page 73: ...load capacitors C19 and C20 The microprocessor may be reset using the pushbutton switch S1 and associated pull up resistor R9 The real time clock integrated circuit U8 has an internal crystal 10 or 50 parts per million frequency precision depending on part number and keeps track of date and time The SAM III includes a battery G1 and voltage steering diodes D3 and D4 for the real time clock Termina...

Page 74: ...tional to the K index The microprocessor RC2 programmable output provides a PWM signal that is proportional to the K index An RC integrator or low pass filter R19 and C21 smoothes the PWM output period proportional to K index This is applied to a dual operational amplifier U11 which provides signal conditioning and buffering The gain of the input operational amplifier is set by R14 P1 and R15 The ...

Page 75: ...I from a nearby HF transmitter that may be operating in the same frequency range as the SAM III sensor multiplexer The SAM III provides an alarm output via the microprocessor RC4 programmable output and relay K1 When the preset K index threshold is reach the SAM III operates the relay which may be used to activate a warning lamp or external relay for a buzzer Not shown in the block diagram but sho...

Page 76: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 74 Main Controller Schematic Diagram ...

Page 77: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 75 Keyboard Schematic Diagram ...

Page 78: ...SAM III Construction Manual See last page for document and copyright information File SAM III Magnetometer Construction doc Page 76 PCB Component Layout ...

Page 79: ...rections When PortMon runs in logging mode for any length of time say 2 hours or more it will gradually use up all PC memory and you will notice that the hard drive continuously runs as Windows constantly swaps the cache between RAM and the hard drive You also will notice the PC becomes sluggish and may appear to freeze and probably has Therefore do not run PortMon in logging mode for more than an...

Page 80: ...UCCESS Length 1 39 20 19 44 PM PIC_downloader IRP_MJ_READ Serial2 SUCCESS Length 1 40 20 19 44 PM PIC_downloader IOCTL_SERIAL_PURGE Serial2 SUCCESS Purge TXABORT RXABORT TXCLEAR RXCLEAR 41 20 19 44 PM PIC_downloader IRP_MJ_WRITE Serial2 SUCCESS Length 1 42 20 19 44 PM PIC_downloader IRP_MJ_READ Serial2 SUCCESS Length 1 43 20 19 44 PM PIC_downloader IOCTL_SERIAL_PURGE Serial2 SUCCESS Purge TXABORT ...

Page 81: ..._downloader IRP_MJ_WRITE Serial2 SUCCESS Length 1 39 20 16 31 PM PIC_downloader IRP_MJ_READ Serial2 SUCCESS Length 1 40 20 16 31 PM PIC_downloader IOCTL_SERIAL_PURGE Serial2 SUCCESS Purge TXABORT RXABORT TXCLEAR RXCLEAR 41 20 16 31 PM PIC_downloader IRP_MJ_WRITE Serial2 SUCCESS Length 1 42 20 16 31 PM PIC_downloader IRP_MJ_READ Serial2 SUCCESS Length 1 43 20 16 31 PM PIC_downloader IOCTL_SERIAL_PU...

Page 82: ... Iss 1 7 Add scope screenshots July 5 2011 Iss 1 8 Minor edits 18 March 2012 Iss 1 9 Updates 19 December 2012 Iss 2 0 Updated drawings clarifications 11 Sep 2014 Iss 2 1 Testing clarifications and updated sensor installation 25 Apr 2016 Iss 2 2 Added images of completed PCB 06 May 2016 Iss 2 3 Completed reformat 11 Jun 2016 Iss 2 4 Added connector contact images 17 Jun 2016 Iss 2 5 Minor edits 02 ...

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