GDP-32
II
INSTRUCTION MANUAL
October 2002 Section 12, Page 38
Damping: Adjustment for transmitter damping resistors. Damping resistance values are
available from 50 to 1550 ohms in steps of 50 ohms. These values can be changed by pressing
Home
SELECT UP
and
SELECT DN
End
. The best choice for damping resistors is a complex function of the loop
size and the electrical resistivity of the area in which measurements are being made. The chart
below offers estimates of damping values for different transmitter geometries.
Tx Loop Size (m) Damping Resistance (ohms)
5 100
10 150
20 250
40 450
80 850
100 1000
12.21 NANOTEM TURNOFF TIMES
The following are some approximate turnoff times for a selection of transmitter loop sizes:
Loop Size Turnoff Time
10 x 10 meter loop
1.2 µs
20 x 20 meter loop 1.5
40 x 40 meter loop 3.0
100 x 100 meter loop 6.0
The NanoTEM program has been used successfully in highly conductive as well as highly
resistive environments.
12.22 NANOTEM FIELD DATA CACHE
At this time, all of the GDP-32
II
programs, except for the NanoTEM program, initialize the data
cache according to the outline in Chapter 7.4. Initialize the NanoTEM data cache as follows:
If you are in the NanoTEM program, get into the first menu and
Press 2 Utilities, then
Press 6 Turn off power, then
Press
Enter
The LOGO screen will now be displayed. This is also where you will enter the program if you
have just turned the receiver on. The cache file may be deleted using either a DOS or
WINDOWS procedure.
To Next Page
Loading...
