User Manual

GMC-I Gossen-Metrawatt GmbH 33
V/Hz, Ω, Temperature, and A/Hz Measurements
5.1.6 Frequency and Keying Ratio Measurements
(METRAHIT⏐X-
TRA⏐OUTDOOR only)
➭ Set the rotary switch to MHz or %.
➭ Connect the measurement cables as shown.
Make sure that a current measuring range (“A”) has not been
activated when the multimeter is connected for frequency or
keying ratio measurement!
Attention!
!
The applied signal voltage may not exceed 5 V.
Frequency Measurement, MHz
A 5 V signal with a frequency of up to 1 MHz is measured and
displayed using MHz as a unit of measure. Pulse frequency
demonstrates the reciprocal value of pulse period.
Keying Ratio Measurement, t
E
/t
P
The ratio of pulse duration to pulse period is measured with
periodic square-wave signals and displayed as a percentage.
Note

The applied frequency must remain constant during keying
ratio measurement.
keying ratio (%) =
pulse duration (t
E
)
pulse period (t
P
)
• 100
COM
V
Temp
Ω
Max. 5 V
!
1 . 0323
MHz
002 . 00
%
MHz
%
MHz
%
U
t
t
E
t
P
t
E
/t
P
Pulse Time Quantities
f
P
pulse frequency = 1/t
P
t
E
pulse duration
t
P
pulse period
t
P
– t
E
interpulse period
t
E
/t
P
pulse or keying ratio
f
P
FUNC
ENTER
Measuring Ranges:
MHz t
E
/t
P
100 Hz ... 1 kHz 2 ... 98%
... 10 kHz 5 ... 95%
... 100 kHz 10 ... 90%