TRANSIENT ELECTROMAGNETICS PROGRAM
Section 12, Page 45 October 2002
12.25 THE NANOTEM CALIBRATE BOX
The NanoTEM Calibrate Box is a resistor-capacitor network that provides a load for the NT-20
Transmitter when operating in the NanoTEM mode, which generates a decay transient suitable
for measurement in the NanoTEM decay windows.
SETUP
Refer to the NT-20 NanoTEM Calibrate Setup schematic diagram showing the setup for testing
the GDP-32
II
with the NanoTEM Calibrate Box. Refer to Section 12.3 to set up the correct
header information for TEM. Follow the steps enumerated below and refer to the figure:
1. Connect the NT-20 transmitter outputs to the corresponding TRANSMITTER jacks (BLUE
and BLACK banana jacks) of the NanoTEM Calibrate Box. Use the 60 cm twisted-pair cable
provided with the calibrate box.
2. Plug the NT-I terminal connector (i.e., black double banana plug with single banana plug
pigtail cable) into a GDP-32
II
input channel corresponding to a NanoTEM analog card. Plug
the pigtail into the COM jack of the GDP-32
II
.
3. Connect the RECEIVER outputs of the NanoTEM Calibrate Box to the input channel
containing the NT-I terminator plug, RED to RED and BLACK to BLACK. Use 10 cm jumper
cables.
4. Connect the NT-20 power cable to a 12Vdc power source and the Transmitter I/O cable from
the GDP-32
II
to the corresponding cable connector on the NT-20.
5. The results plotted in the NanoTEM Calibrator Decay Transient figure show the transient
curve for 1.2 µs sampling and 1.6 µs sampling, respectively with the antenna delay set at 2 µs
and the Tx delay set at 1.5 µs. The ALIAS filter was set to IN. The receiver moment was
set for a standard 5mx5m loop (RxM = 250). The output current of the transmitter should be
adjusted to 1 A.
The recorded signal levels are normalized by current so it is important that the output current be
set to one amp if decay curves are to be compared to those in the figure. Also remember that you
are comparing curves with the same total delay time.
To Next Page
Loading...
