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EM61MK2 Data Logging System (DAS70/61MK2)
1. Introduction
1. Introduction
1. Introduction
1. Introduction
1. Introduction
The Geonics EM61MK2 Data Logging System (DAS70/61MK2) consists of a field computer
Allegro (or Pro4000), data logging program EM61MK2A (or EM61MK2P for Pro4000), and
associated cable to connect the Polycorder to the Geonics EM61-MK2 instrument. The program
EM61MK2A is designed for the Allegro field computer, although, if necessary it can be used with
any other IBM compatible computer running a MS DOS operating system and equipped with
serial port. The only disadvantage of using a standard laptop computer, will be small size of the
display which is limited for the Allegro. This documentation describes the use of the EM61MK2A
program used with the Allegro field computer, and the Geonics EM61-MK2.
The program EM61MK2A records data together with a time stamp at each station. Data files
created with this program can be used to position a survey according to locations recorded separately
by a Global Positioning System (GPS).
The EM61MK2A will also accept NMEA-0183 compatible data from a GPS receiver directly
connected to an Allegro field computer. GPS data which are embedded in the EM61MK2 data file
can be processed later in the Geonics DAT61MK2 program. The connected GPS must be able to
stream NMEA-0183 compatible messages. The EM61MK2A 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.
Program EM61MK2A acquires and records survey data from the EM61-MK2 system, under the
control of the operator. It also records various field information such as survey line number (line
name), starting station, increment, comments, etc. Readings can be displayed in text or graphic
mode. Readings are displayed in real time in mV. In addition, the program allows to monitor the
instrument output while data are not recorded. The EM61MK2A also continuously monitors the
condition of the instrument battery, without leaving the program. The EM61MK2A also provides
the possibility of automatic nulling of the instrument output.
The program allows the user to set the EM61-MK2 into a specific instrument mode of operation:
AUTO, Wheel, or Manual modes. In AUTO mode readings can be automatically recorded in desired
time intervals. In WHEEL mode readings are triggered by a counter installed at the EM61-MK2
wheel assembly, and in MANUAL mode readings are triggered manually by the operator. The
program allows you to record data while using the standard EM61-MK2 antennas (0.5 x 1 m, 1 x 1
m, or 0.5 x 0.5 m sensors) as well as Geonics EM61-MK2 Hand Held sensor.
Survey setup parameters are saved in a file, therefore they can be automatically used during subsequent
data collection sessions. In addition, ten preset survey setups are provided. These setups are user
selectable, they can be edited and saved for future use.
The EM61MK2A also continuously monitors the condition of the instrument battery, without
leaving the program.
In addition to logging EM61-MK2 data, the EM61MK2A provides data file management tasks.
The program allows you to upload data files to a PC running the DAT61MK2 program. It also has
options allowing viewing and deleting data files. Data files are always saved to the programs current
directory. Data file names, which can be set by the program based on the computer clock or they
are user specified, have extension names R61.
Summary of Contents for EM61MK2A
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