SubSurface Instrument BHG-1 Instruction Manual

16

SubSurface Instruments, Inc.

1230 Flightway Drive

De Pere, WI 54115

PH:920-347-1788 FX:920-347-1791

www.ssilocators.com

Email: [e-mail]

BHG - Bore Hole Gradiometer

(Short Sensor, for down hole work)

Bore Hole Gradiometer

Instruction Manual

2

Table of Contents

Features ....................................................................... 3

Controls Description ................................................... 4

Display Description ..................................................... 5

Function ....................................................................... 6

Operation ..................................................................... 7

Connections ................................................................. 8

RS-232 Interface ......................................................... 9

Maintenance .............................................................. 10

Specifications ............................................................ 11

Included Accessories ................................................. 12

Warranty Statement ................................................... 13

Notes .......................................................................... 14

Contact Information .................................................. 16

15

Notes:

14

Notes:

3

Features

 Standard unit with internal battery housed in a high impact

ABS case.

 Included accessories:

 Manual
 Wall transformer for recharging battery
 Rechargeable sealed lead acid battery (internal)
 12 Volt auxiliary power cable
 RS-232 Cable
 30’ Sensor cable

 Accessories store in compartment in lid.

 Electronic control unit.

 Titanium encased waterproof Sensor .

 Waterproof optional cables available: 50’, 100’

Other lengths special order.

 Commonly used for down hole testing for ordnance, buried

drums, etc.

 Can be used in shallow water, streams, and ponds searching

for ferrous metal objects.

 Low Battery indicator on LCD display.

4

1. ON .......................................................................... Power ON

2. OFF ...................................................................... Power OFF

3. Volume ............................................... Raise or lower volume

4. Gain ............ Increase or decrease gain from .3mG to 100mG

5. Zero ................................... Manual adjustment of zero offset

6. Auto Zero ............. Automatic adjustment to “NULL” output

7. Battery Check ........................ Press to check battery voltage

Controls Description

13

Warranty Statement

SubSurface Instruments, Inc. warrants the BHG-1 to be
free from defects in material and workmanship for a period of
twelve (12) months from date of shipment to original purchaser,
subject to the following conditions.

Our obligation under this warranty is limited to servicing
or adjusting any product returned to the factory for this purpose,
and to replace any defective part thereof. Such product must be
returned by the original purchaser with proof in writing, to our
satisfaction, of the defect. Serial numbers must be intact. Abuse
and/or batteries or battery damage is excluded from the warranty.

SubSurface Instruments, Inc. shall not be liable for any
injury to persons, or any other special or consequential damages
sustained or expenses incurred by persons from the use of any
product or repair.

12

Included Accessories

Serial Port Cable

Sensor Cable

12 Volt Power Cable

Wall Transformer

5

Display Description

1. Bar Graph (top) .............. Shows signal strength and polarity

2. BATT Icon .................. Flashes when battery needs charging

3. Numeric output ............ Indicates signal value in Milligauss

................................................. dependent upon range setting,

................................................ or battery voltage when BATT

...................................................... CHECK button is pressed.

4. Bar Graph (bottom) .......... Indicates current Range selected

.............................................................. by the GAIN buttons.

5. Numbers across bottom ........ 100, 30, 10, 3, 1, .3 are ranges

........................................................................... in Milligauss.

6

Function

The BoreHole Gradiometer (BHG) responds when the magnetic
field strength measured at the two sensor elements inside the Sen­sor housing are different. This difference is measured in
“Differential Milligauss” and is reported to the user via the LCD
display and the audio speaker.

A headset may be used in noisy environments and will disable the
speaker when connected.

The RS-232 interface allows control and recording using a per­sonal computer with a serial COM port.

The LCD
Bar
graph fills to the left or the right side of the display depending on
signal polarity. Left is Negative and right is Positive. As the sig­nal increases in strength, the audio pitch increases in frequency.

11

Specifications

Controls:

ON, OFF

Volume UP and DOWN

Range setting (Gain or Sensitivity) UP and DOWN

Zero, Plus and Minus

Auto Zero - Automatic self-adjusting

Battery Check

Outputs:

Audio Frequency pitch (Speaker & jack for headset)

Visual LCD Display

Bar graph - Range GAIN setting - Milligauss
RS-232 PC connection (cable included)

Control all keypad functions
Data log range, keypad & signal settings
Works with hyper terminal or equivalent

Power Options:

Internal battery: 12 volt, 7.2Ah sealed lead acid

Battery Life: 72 Hours continuous use

Charges to full overnight
External Power 12 to 15 volt, cable included
Internal battery charging circuit is enabled when external
power or the wall transformer is connected .

Operating temperature range:

-20F to 150F (-29C to 66C)

Dimensions:

Electronics: 18.5” X 14.5” X 7.5”
Sensor: 1.625” X 17.5”

10

Maintenance

Keep the unit as clean as possible, especially the Electronics key­pad panel. Do not use an abrasive cleaner on the keypad overlay
or the LCD lens.

The Titanium encased sensor has no user serviceable parts. In the
event of a failure, the sensor should be returned to the factory at
the address listed at the end of this manual.

The battery and charging circuit are located inside the electronics
unit and should not need servicing for quite some time. In the
event that the battery weakens or fails, return the unit to the facto­ry for replacement.

Battery Charging:

Connect the wall transformer to the CHARGE connector located
on the right side of the case. The Red LED will illuminate during
charging and will extinguish when the battery is fully charged.
While plugged in it will provide a trickle charge but the LED will
be off.

Repair Service:

Should you need to return the system to the factory for service,
send it to the address listed on the last page of this manual. Pack
the unit properly to protect it during shipping. No authorization is
necessary. Please include all your company information for re­turning the unit.

7

Operation

Connect the sensor to the electronics using the sensor cable be­fore turning the system on. Press the green ON button to turn on
the BHG . To turn OFF press the red OFF button. The RS-232
interface cannot be used to turn the BHG on or off.

To check battery condition press the BATT CHECK button and
the battery voltage will display on the LCD.

Place the sensor in the water using your towing arrangement.

As the sensor is towed across a target the audio output will in­crease in pitch relative to the strength of the target. The bar graph
at the top of the display will also darken the bars to the left for a
negative polarity and to the right for a positive polarity.

Adjust the GAIN up or down as needed to maintain proper sensi­tivity.

Towing the sensor horizontally will produce two peaks as the sen­sor passes over a target. Towing vertically will produce one peak
over the same target.

When attaching the sensor to a tow rig, keep the sensor away
from ferrous metals. Although the sensor cable can be used to tow
the sensor, it is not recommended using it to tow a sled rig.

The sensor can be held by a diver to locate objects but will need
communication between the diver and the topside operator.

Although the electronics case is water proof when closed, it is
recommended that it be kept out of the elements as much as pos­sible when open as water could seep through the foam. Water
damage to the internal parts is not covered under warranty.

8

Connections

The headphone jack has a water resistant cover. Lift open to plug
in a stereo phone plug to listen with a headset in noisy environ­ments.

Replace a blown fuse with a 1/4 amp slow blow.

Use the included RS-232
cable to connect the MUL
to a computer.

To run on external power
or to charge the battery in
the field, connect the exter­nal DC power cable to the
POWER connector. Con­nect the other end clips to a
12 to 15 Volt DC power
source. Red to positive and
Black to negative.

The sensor cable is con­nected to the SENSOR
connector.

9

RS-232 Interface

COM Port settings:

Baud rate 9600
Bits 8
Parity NO
Stop bit 1
Flow Control None

Program:

Use Hyper Terminal or custom software to communicate. Turn off echo. The
unit will echo any character it receives to verify communication.

Commands:

v Lowers volume
V Raises volume
g Increases range (lower gain)
G Decreases range (raise gain)
b, B Check battery voltage
r Turns OFF status report
R Turns ON status report
? Causes a status report to be sent
l Specifies short status report
L Specifies long status report
d Turns off debug mode
D Turns on debug mode
z Zero + 1 step per command
Z Zero - 1 step per command
a, A Initiate auto zero
s, S Toggle sample rate

Report String Description:

Long version using send character = “L”, Total characters = 58

$SIG=_±XXXE-X,_GAIN=_X,_BAT=_XXXE-1,_VOL=_X,_Z=_XXX,_A=_X!

Short version using send character “l” (lower case L), Total characters=22
$SIG=_±XXXE-X,_GAIN=_X

Underscore in string represents a SPACE character. It is not output as an un­derscore but as a space.

Example: $SIG= ±XXXE-X, GAIN= X, BAT= XXXE-1, VOL= X, Z= XXX, A= X!