Geonics Limited EM61LX2 User manual

EM61LX2
1745 Meyerside Drive, Mississauga, Ontario, Canada L5T 1C6
Tel: [phone] Fax: [phone]
E-mail: [email protected]
Geonics Limited
April, 2023
Version 1.13
EM61LX2 DATA LOGGING SYSTEM
FOR FIELD COMPUTER MESA2 (MS Windows 10)
OPERATING INSTRUCTIONS

Table of Contents
1. Introduction ................................................................................................ 1
1.1 Program Requirements ......................................................................... 2
1.2 Installing EM61LX2.............................................................................. 2
1.3 Data Files Transfer ............................................................................... 2
1.4 Running EM61LX2 Program.................................................................. 2
1.5 Main Menu......................................................................................... 3
Short description of Main Screen options ...............................................................3
2. Survey Setup ............................................................................................... 7
3. Logger Setup............................................................................................. 11
3.1 Description of Parameters.................................................................... 12
4. Set Port for GPS......................................................................................... 19
4.1 GPS Port Setup.................................................................................. 19
4.2 Monitoring GPS Receiver Output ........................................................ 21
5. Display Options ........................................................................................ 25
6. Logging Data............................................................................................ 29
6.1 Monitoring Mode .............................................................................. 29
Description of Monitoring Mode options..............................................................34
6.2 Stand By Mode.................................................................................. 42
6.3 Logging Mode................................................................................... 44
6.4 Stand By Mode Field Options ............................................................. 45
6.5 Logging Screen Layout in the Portrait Display Orientation...................... 52
Appendix A ....................................................................................................... 55
A.1 Description of Data File in EM61LX2 (L61) Format................................ 55
A.2 Conversion Factors............................................................................ 58
A.3 Example of File in EM61LX2 Format.................................................... 60

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EM61LX2 Data Logging System (DAS70-M2)
1. Introduction
e Geonics EM61LX2 Data Logging System (DAS70-M2) consists of a eld computer Mesa2 with
MS Windows 10 operating system, data logging program EM61LX2, and wireless Bluetooth con-
nection or associated cable to connect the Mesa2 computer to the Geonics EM61-LX2 instrument.
e program is prepared for the MS Windows 10 tablet Mesa2 (manufactured by Juniper Systems)
operated in the landscape as well as in portrait display mode (landscape mode is used in this manual
mainly). However the program can be used in other Windows 10( or 7) based eld computers with
vertical and horizontal oriented displays. e minimum supported display resolution is 800 x 600
pixels. In case high resolution display is employed, it is advised to set fonts to 125% or 150% to
increase legibility of the screen. e maximum size of program main windows is 1024 x 762 pixels.
e EM61LX2 program acquires and records survey data from the EM61-LX2 system, under the
control of the operator. It also records various eld information such as survey line number (line
name), starting station, increment, comments, etc. Data is displayed in graphic and text mode.
Readings are displayed in real time in mV. In addition, the program allows you to monitor the in-
strument output while data is not recorded. Readings can be automatically recorded or displayed in
Monitoring mode at user specied time intervals. e EM61LX2 program continuously monitors
the condition of the instrument battery, without leaving the program. e EM61LX2 also provides
the possibility of automatic nulling of the instrument output as well as calibrate Filter Channel
factors at any time during the survey.
e program provides dual graphic display - modulated colour ribbon graphs and proles. It can
also display measured channels Early (ChE) and Late (ChL), or Filtered (ChF) for each sensor.
Displayed set of channels (E and L, or F) can be toggled at any time during Monitoring instrument
data. Furthermore, for two sensors channels are named for the left sensor: ChLE (Left-Early), ChLL
(Left-Late), and similarly for the right sensor: ChRE (Right-Early) and ChRL (Right-Late). It is
always assumed that the left sensor is on the left (and the right one on right) of center point while
facing direction of a system movement. If one sensor is employed in the instrument then labeling
for Left sensor applies. In case of GPS based positioning it is the only method to determine proper
location of each coil.
e EM61LX2 will accept NMEA-0183 compatible data from the Mesa2 built in GPS receiver
or external GPS directly connected to the eld computer. GPS data which are embedded in the
EM61LX2 data le can be processed later in the Geonics DAT61LX2 program. e connected
GPS must be able to stream NMEA-0183 compatible messages. e EM61LX2 uses two NMEA
messages GGA and GSA. While message GGA is mandatory, the GSA string is used only to provide
information related to the GPS signal quality during data collection.
e EM61LX2 program records data together with a time stamp at each station. Data les created
with this program can be used to position a survey according to locations recorded separately by a
Global Positioning System (GPS). Survey setup parameters are saved in a conguration le, therefore
they can be automatically used during subsequent data collection sessions.
Data les are saved to the user selected data directory. Data le names, which can be set by the
program based on the computer clock or user specied, have extension names L61. Files can be
converted to LX2 format and viewed in DAT61LX2 program. Number of readings in a data le
is limited only by the hard drive capacity, however it is strongly recommended to avoid huge data
les (i..e one to two hours long data les are adequate). e maximum speed of data collection is
approximately 18 readings per second assuming 5 Hz (or less) GPS input.

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1.1 Program Requirements
To successfully use this software, you will need :
Computer
- Mesa2/Mesa3 eld computer (or similar) operating under Windows 10,
- minimum 4 Gb of RAM memory,
- USB port or other mean to transfer les,
- minimum 800 x 600 pixel display resolution,
- serial Ports:
one serial port for instrument plus one serial port if directly connected GPS receiver
is to be used (USB to multiple RS-232 ports adapters can be used) or available
Bluetooth connection.
Geonics EM61-LX2
e EM61-LX2 instrument with associated cables (or Bluetooth option).
e EM61LX2 program may be stored on DAT61LX2 CD disk, USB memory stick, or it is available
for download from the Geonics web site. All necessary conguration les (with extension names
.INI) are created in your eld computer after the program is run for the rst time.
1.2 Installing EM61LX2
e program consists of a standalone le EM61LX2.exe, no DDLs nor other libraries are required
to run this program.
If the program le is included separately on the DAT61LX2 CD disk, or downloaded from the web
site it can be installed by copying the SetupEM61LX2.exe le and executing standard installation
procedure.
After you run the program for the rst time it will create permanent conguration le (.INI) which
contains all needed program settings. If the above le does not exist on the default drive it will be
created with default parameters during the rst execution of the program.
e EM61LX2 data les contain extension name L61 and their base names should be limited to
8 characters.
1.3 Data Files
Data les are saved in the eld computer with extension L61. Data les with extension L61 are binary
raw data les. ese les have to be converted to DAT61LX2 format with extension LX2 (option
"Convert Files" in DAT61LX2). en they can be loaded and processed in the DAT61LX2 program.
1.4 Running EM61LX2 Program
Start EM61LX2win by double clicking the EM61LX2 icon in the Start|Programs menu, in Win-
dows Explorer, or on the desktop if a shortcut was created. At the start, EM61LX2 displays the
following screen.

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EM61LX2 Data Logging System (DAS70-M2)
e EM61LX2 is a command button and dialog driven program. Command buttons can be ex-
ecuted by taping (if touch screen is used) or clicking with the left mouse button, or by pressing the
indicated (underlined) character on the keyboard, or by using TAB to scroll through the buttons
and ENTER to execute. In the Main Screen of the program Up and Down arrow keys can be also
used to scroll through the buttons.
e Main Screen appears always as the rst window after the program is started. It contains the
name of the program, its version number, and list of command buttons with available options on
the right side. e major , left portion of the window contains information about current survey
and system settings. is section is updated in real time as soon as the program parameters are
changed in dialogs.
1.5 Main Screen
e Main Screen always appears after the program is started. It contains the name of the program,
its version number, and a list of buttons representing the available options. e EM61LX2 Main
Screen for a computer sporting landscape display orientation is shown below while the same screen
for the computer with portrait display mode is shown in Figure on the next page.
ese options are selected by using tapping buttons, or from keyboard using TAB/ENTER or
shortcuts indicated by underline label characters. In case of Main Screen buttons the Down and
Up arrow keys and <ENTER> can be used as well.
Short description for each of the options follows.
Short description of Main Screen options
Monitor/Log
is option allows to monitor and log the EM61-LX2 output. Monitor/Log screen starts
always in Monitor mode, and then after a data le is created Logging mode is available.
Monitor mode provides several options: the instrument Oset Nulling, performing Filter
Calibration, monitoring EM61-LX2 battery level, etc.

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Survey Setup
e Survey Setup dialog will be displayed. e EM61-LX2 update rate, and all survey set-
tings (survey line name, increments, etc.) can be specied in this dialog.

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EM61LX2 Data Logging System (DAS70-M2)
System Setup
Dialog window that is associated with this option is used to set number of sensors, lter
values, serial ports numbers, specify type and parameters for Alarms.
Set GPS Port
e GPS Port Setup dialog allows to disable and enable GPS data acquisition. is option
is also used to set the serial port number used for GPS input and to specify necessary se-
rial port communication settings. is dialog has also option for specifying GPS antenna
osets. GPS monitoring window can be accessed from this dialog as well.
GPS Monitoring
e program enters terminal mode and displays input from GPS. is function is very
convenient to test communication with GPS receiver and examine GPS stream type..
Display Options
e dialog which will allow you to specify colour and thickness of prole lines will appear.
is dialog provides also choice of linear or compressed amplitude used for prole display.

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View Files
is option allows to review data les saved in the eld computer.
Exit
is option will terminate the program execution.

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EM61LX2 Data Logging System (DAS70-M2)
2. Survey Setup
e Survey Setup dialog, presented below, contains several parameters which aect two important
procedures: instrument settings (frequency of data collection) and survey geometry layout (survey
line names, line spacing, start station, station increment, etc.).
Description of Options and Parameters:
Update Rate
is parameter describes number of readings per second that will be taken. Clicking on
the down arrow next to the text box labeled Update Rate opens a drop-down box showing
available settings: 19 Hz, 9 Hz, 6 Hz, 4.5 Hz, 3.6 Hz, 3 Hz, 2 Hz, and 1 Hz.
is parameter describes number of readings per second that will be taken. e EM61-
LX2 frequency is based on the base data output of approximately 18 readings per second.
erefore selections reect the nearest possible base frequency of the instrument, i.e. at
user selection of 18 Hz program will record every record, at selection 9 Hz the program
will record every 2nd reading, selection 6 Hz will cause program to record every 3rd read-
ing, and so on.

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Survey Line (survey line name)
Activate text box by tapping or using TAB key and then enter desired name (number) for
the survey line.
is is a user’s tag number/name for the prole line. e length of the name can not exceed
8 characters. e line name is usually used as a coordinate perpendicular to the survey lines
direction. For example, when survey lines are laid out along W-E direction stations describe
W-E coordinate, while Line names may describe S-N (vertical on a map) coordinate.
Line Incr. (survey line name)
Activate text box by tapping or using TAB key and then enter desired for the survey line
increment.
is parameter species the distance by which survey lines will be separated. is setting
will be used to determine number (name) of the next survey line.
Sequence
Tapping on the down arrow next to the text box opens a drop-down box showing the avail-
able settings, or when the keyboard is used activate the text box and then by using up or
down arrow keys select one of two available items: Alternate and One Way.
Alternate is used when neighboring lines are surveyed in the opposite direction, which is
the most common procedure during eld surveys.
One Way is used when each survey line is traversed in the same direction.
e choice of this parameter will aect the default start station, a signature of the station
increment, and line direction when parameters for the next survey lines is determined.
Direction
Tapping on the down arrow next to the text box opens a drop-down box showing the
available options, or when the keyboard is used activate the text box and then by using
up or down arrow keys select one of four available settings: East, West, South, and North.
is parameter indicates the heading of the survey line.
Start Station (start station of a survey line)
Activate text box by tapping or using TAB key and then enter the desired value for the
start station.
is parameter species the starting station number for the selected survey line. is value
is used in conjunction with Station Increment to calculate the current station number for
display purposes.

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EM61LX2 Data Logging System (DAS70-M2)
Stn Increment (station increment)
Activate text box by tapping or using TAB key and then enter the desired value for the
station increment.
is parameter species the station increment for the selected survey line. is value is used
in conjunction with Start Station to calculate the current station number for display purposes.
After all the parameters in the Survey Setup dialog are updated tap the button OK or press ENTER
key to accept the displayed settings. e program will return to the Main Screen. Updated settings
will be written to the initial le and they will be given as default parameters in the subsequent
Survey Setup dialog.
To return to original settings (state before this dialog was selected) tap or click on the Cancel but-
ton. All parameters will be reset to initial settings and the program will return to the Main Screen.

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EM61LX2 Data Logging System (DAS70-win)
3. System Setup
is option allows you to specify numerous important parameters as instrument setup, serial ports
assignment, program setting and alarm type. A separate Alarm Setup dialog is also accessible dur-
ing measurement session therefore alarm type and corresponding parameters can be adjusted later
during data logging. e System Setup dialog is presented below in two Figures for program used
at computer landscape and portrait display orientation. Despite dierent layout all parameters are
exactly the same.

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3.1 Description of Parameters
EM61-LX2 Type
e EM61-LX2 can be used in a standard mode, meaning that readings include normalized
for TX current, or in the N.C.C. (No Current Correction) mode where TX current nor-
malization is not applied. Normalization factors are calculated dynamically during data col-
lection (regardless of Monitoring or Logging mode) and correction is applied continuously.
When N.C.C. type is selected then the program does not use transmitter current normal-
ization to reduce EM61-LX2 readings to the same current level. It is mandatory for setups
where external transmitter antenna is employed. Type N.C.C. can be also chosen when
transmitter current normalization is not desired for any reason.
No of Sensors
e EM61-LX2 can be used with one or two sensors connected. Select number sensors
(antennas) connected to the console. Selection is "1 Sensor" or "2 Sensors" (default).
If two sensors are selected, the sensor number 1 is the one located on the left and sensor
number two is located on the right while facing both antennas in the direction of movement.
When one sensor is selected then it is considered by the program as the left sensor. Labels
"sensor one" as well as left sensor are "synonymous", as for example during specifying Filter
Factors below.

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EM61LX2 Data Logging System (DAS70-win)
Filter Factor Left / Filter Factor Right
Filter Factors used to remove soil magnetic susceptibility in surveyed area must be specied
separately for each antenna, Left Coil (number 1) and Right Coil (number 2). Filter Factors
for each antenna can be determined automatically later during data acquisition stage. In
case automatic lter determination won't be used, values entered here will be used during
data collection and embedded in data le.
Default value for each lter factor is 310, and accepted range of ler is 100 to 900.
Battery Warning
Specify instrument battery warning level. When the EM61-LX2 battery voltage will reach
and drop below specied value the program will display battery voltage on the red back-
ground.
EM61-LX2 Port
e number of serial port that is assigned to the EM61-LX2. Available selections: COM1
to COM60. e program default is COM1. Communication parameters for the selected
serial port are set by the program, since the EM61-LX2 operates at xed settings: Baud
Rate (9600), Parity (N), Data Bits (8), and Bit Stop (1).
is port must be dierent than the port specied in the list box "GPS Port:" (see below) or
in the GPS Port Setup dialog window (see chapter 4), otherwise a message will be displayed
and ports will have to be reassigned.
Select port number in the drop-down list box.
GPS Port
e number of serial port that is assigned to the GPS receiver. Available selections: COM1
to COM60. e program default is COM2. Communication parameters for the selected
serial port can be set in GPS Port Setup dialog. e GPS port can be also assigned in the
latter dialog.
is port must be dierent than the port specied as the EM61-LX2 serial port.
Select port number in the drop-down list box similarly to EM61-LX2 port assignment
procedure.

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e wireless Bluetooth connection (if available) between EM61-LX2 and Mesa2 (or similar eld
computer) must be set up only once (see Windows 10 Settings), then it works the exactly same way
as physical cable connection assuming that proper serial port (COMx) is selected. To check which
serial port (COM) is assigned for Bluetooth communication check Bluetooth settings in Windows
10. Both EM61-MK2 and GPS receiver can use wireless connection separately or concurrently.
Metronome
Two selections are available: Yes or No. e audible click will be generated at uniform rate
when this option is enabled. At fast rate (above 10 readings/s) the sound may appear not
very uniform, however this does not aect quality of data acquisition.
e Metronome mode is switched o automatically if any audio Alarm (see next section)
is enabled.
Display Units
ree selections are available: Meters, Feet or US Survey Feet.
Pause key
Four selections are available: any non arrow/numeric key, Enter,Space Bar, and Pis
feature is used to pause data recording during logging session. Default setting any key can
be changed to one of the three specic keys for eld conditions where a logger key can be
accidentally pushed causing unwanted stop of data logging. When Windows based tablet
computer Mesa2 or Mesa3 is used the best setting is <any non arrow/numeric keys> or
<ENTER> option. User specied keys P1, P2, and P3 may have various assignment, and
arrow keys located on Mesa2 keyboard are reserved for Fiducial Marker.
Soft Marker Key
A software based ducial marker is available in the EM61LX2 program. ere are two
available selections for the Soft Marker Key: Disabled and any arrow or numeric key.
When the latter option is selected pressing any arrow key on tablet (Mesa2 or Mesa3)or any
numeric key (from 0 to 9) on any computer equipped with hard keyboard during logging
session will tag current station as a station with ducial marker. It acts exactly the same
way as a standard hardware based marker in other instruments and marker is tagged at the
moment reading is recorded. erefore a marker key should be pressed while reading is

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EM61LX2 Data Logging System (DAS70-win)
taken, and it is recommended to keep it depressed for next reading or two (data processing
program recognizes only the rst marker in sequence).
Enable the Soft Marker by selecting any arrow or numeric key or deactivate this option by
selecting Disabled (see Figure below).
Disable Pause Button for Touch Screen/Mouse
When desired a Pause button can be disabled. is may be desired in harsh terrain when
accidental screen touch by operator, branches, or heavy rain drops may accidentally pause
readings. When this option is checked the Pause action must be executed by the selected
Pause key.
Alarms Options
ere are two types of alarms (not counting the third: Disabled) in the EM61LX2 program. e
Simple Alarm is triggered whenever the indicated amplitude level is exceeded. e Enhanced Alarm
contains four parameters that describe minimum and maximum levels, width of anomaly, and
number of descending points. e enhanced alarm option can be used to design alarm settings for
specic targets.
Alarm is shown visually as red squares displayed under corresponding sensor. ere are also two
types of audio alarms: Voice Indication and Ringing. When the Voice Indication is selected human
voice indicates sensor that (coil) that triggers alarm (for example: One - left sensor, or Tw o - right
sensor). e Ringing type provides ringing sound whenever one of sensors alarm is triggered.
Description of Options and Parameters:
Alarm
is option allows you to selected one of three settings for alarm: Disabled, Simple, and
Enhanced.
Tapping on the down arrow next to the text box labeled Alarm Type opens a drop-down
box showing the available settings, or when the keyboard is used activate the text box by
pressing TAB key and then by using up or down arrow keys select one of the three avail-
able items: Disabled, Simple, and Enhanced. Depending on the selection corresponding
portions of the dialog are enabled. In the Figure above (this page), when the Disabled item
is selected all alarm parameters are disabled.

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Sound
is option allows you to specify the sound type of alarm. Tapping on the down arrow next
to the text box labeled Sound Type opens a drop-down box showing the available settings,
or when the keyboard is used activate the text box by pressing TAB key and then by using
up or down arrow keys select one of the three available items: Disabled, Voice Indication,
and Ringing.
When the Voice Indication is selected human voice indicates sensor (coil) that triggers
alarm: One - left sensor, Tw o - right sensor, or One And Two if amplitude indicates target
located between two sensors. e Ringing option provides ringing sound (minimum dura-
tion about 1 second) whenever alarm is triggered for any sensor.
Alarm Level (Simple Alarm only)
Specify amplitude value that will trigger alarm. Whenever the target response will be larger
than specied amplitude the alarm will be triggered. Visual alarm will be always displayed,
while an audio alarm will sound depending on the Sound Type selection.
Parameters described below can be selected only when the Enhanced Alarm is selected. When En-
hanced Alarm is selected conditions for all set parameters must be reached to trigger alarm.