ETS-Lindgren FP5080 Isotropic Electric Field Probe (Archived) - Manual (Page 18)

Isotropic Electric Field Probe
© ETS-Lindgren, June, 2005
Revision F, Part # H-600057
18
PROBE POWER SUPPLY
A sealed rechargeable 3.6 VDC NiCd battery, which drives both
the analog and digital power supplies, powers the HI-
4450/FP2080/FP4080/FP5080 probe; separate power sources
provide isolation between the analog and digital circuitry. With
the probe switch in the ARM position, battery voltage is applied
to the power switch, which routes this voltage to the power
supply, enabling the microprocessor.
ZEROING
When the receiver sends a zero command, the probe must be in
a zero field environment. This is because the zero command
causes the multiplexer (via the processor) to perform a normal
read cycle on the composite axis signal. This procedure is
executed for all ranges. When the processor receives all the
zero-field values, it stores them in a special register; these
values are subtracted from all subsequent measurements.
Therefore, a probe that is zeroed while it is not in a zero field
environment will give erroneous readings.
NOTE: The probe uses volatile random access memory
(RAM) to store the zero values. If the power to the
probe is cycled, the zero values will be lost.
APPLICATION CONSIDERATIONS
The following subsections contain information designed to help
you maximize the effectiveness of the HI-
4450/FP2080/FP4080/FP5080.
OUT-OF-BAND CONSIDERATIONS
Although the HI-4450/FP2080/FP4080/FP5080 is nominally
rated for operation from 80 MHz to 40 GHz, it responds to
signals both above and below these frequencies. Such
responses must be taken into account when performing certain
operations, such as zeroing.
Archived 4/02/10