Boonton 9240 RF Voltmeter - Manual (Page 48)

Boonton 9240 Series RF Voltmeter
The terminated Model 952009 RF Probe should not be subjected to continuous overload of more than 4 volts (DC + RMS
AC) in order to avoid excessive heating of the terminating resistor. Exceeding these limits may result in permanent damage.
4.4 Connection Recommendations
1. The Model 952001B probe is equipped with a detachable tip and ground lead. For measurement of signals below
approximately 100 MHz, this tip provides a convenient means for making both signal and ground connections.
2. For frequencies above 100 MHz, the probe tip should not be used because the series impedances of the connection will
affect the voltage level at the probe and cause an error in measurement. For high impedance votage measurements,
connection should be made directly to the center contact of the RF probe, with the ground connection kept as short as
possible. For matched impedance measurements, one of the various terminated adapters, tee adapter or Model 952009 Probe
should be used. Refer to Figure 4-1.
Figure 4-1. Attachment of Model 952003 to (Type N) Tee adapter to Model 952001B Probe
And Model 952014 50 Ohm Termination
4.5 Low Level Measurements
The instrument will provide reliable, repeatable measurements of signal levels as low as 200 microvolts. Useful indications
extend down to 50
µ V. Zeroing of the instrument is essential when using the lower ranges in order to achieve the specified
accuracy. Zeroing is also strongly recommended for all ranges up to 30 millivolts. Refer to Section 4.1 for the zeroing
procedure.
Operation
4-2