High Frequency Measurements - Philips PM2521 Gebrauchsanleitung

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6.4.2.4. High frequency measurements with HFprobe PM 9210 and accessory set PM 9212 (Fig. 28, page 150).
GENERAL
The HF probe PM 9210 is suitable for measuring HF voltages from 150 mV to 15 V in a frequency range from
100 kHz to 1 GHz.
For HF voltages from 15 V to 200 V a capacitive attenuator with an adjustable transfer ratio of 100:1 which
is included in the accessory set PM 9212.
A*-
»
HIGH FREQUENCY MEASUREMENTS
— Select function V-n-r with the function selector.
— Select the manual or automatic ranging mode with pushbutton AUTO/MAN*.
Remark:
Manual ranging is indicated with a * on the display.
In automatic ranging mode the UP level is 21000 and the DOWN level is 01800.
— Select in manual ranging mode the correct range with pushbuttons UP or DOWN.
Remark:
Available ranges are: 200.00 mV
2.0000 V
20.000 V
200.00 V
2000.0 V
Only ranges 200 mV, 2 V and 20 V are being used. Overload is indicated with OL on the display
(Display >21000).
— Connect the HF probe PM 9210 to the PM 2521 as shown in figure 28, page 150.
Remark: «
To ensure reliable results when using probe PM 9210, special attention should be paid to the earthing when
measuring at high frequencies. The connection between the object to be measured and the probe should
therefore be as short as possible and the earthing of the probe should as far as possible be free from self¬
inductance. The accuracy depends on the way in which the earthing is established. A suitable earthing point
will not always be available in the immediate vicinity of the point to be measured. It is advisable, therefore,
to perform the measurements via the T-piece (PM 9212). For accurate measurements above approx. 100 MHz,
the use of the T-piece is imperative. To enable measurements in the non-linear range, a calibration chart is
t supplied with the probe.