Control Elements Of Hm8021 - Hameg HM8021-4 Handbuch

C o n t r o l e l e m e n t s
Control elements
OF (LED)
This LED is lit when an overfl ow ocurs. This
depends on the selected gate time and on the
frequency of the signal applied.
GT (Gate Open; LED)
The gate indicator is lit when the gate is open
for measurements. This time equals the pre-
selected gate time and a synchronization time.
The gate cannot be open for a time smaller
than 1 period of a signal.
Gate Time (pushbuttons + LEDs)
The gate time is selectable in steps of 0.1s, 1s,
10s.
EXT. (LED)
In the GATE EXTERNAL position, the counter
will expect an external control signal, and will
not measure until such a signal is supplied.
Display Hold (pushbutton + LED)
Depressing the DISPLAY HOLD pushbutton
sets the display time to infi nity and freezes
the last measurement result. A new measure-
ment can be initiated using the reset pushbut-
ton. Measuring will restart when Display Hold
is switched off. Display Hold starts and stops
counting in the TOTALIZE function mode.
20
Subject to change without notice
Function indicators
LEDs (Refer to "Measuring functions")
Function (pushbuttons)
The "left" and "right" pushbuttons select the
desired function. The appropriate LED is lit
when a function is selected. The default value
when switching power on is Frequency A.
OFFSET (pushbutton + LED)
The displayed value becomes the reference
value. (Not available with the TOTALIZE func-
tion).
RESET (pushbutton + LED)
Stops a measurement and clears the display
in normal measurement mode. When de-
pressing the button in DISPLAY HOLD MODE
the counter performs a single measurement
(one shot) on release of the button. When the
OFFSET MODE is activated, depressing RESET
shows the reference value (which is the actual
offset). Reset is active as long as the button is
de pressed.
INPUT C (BNC-connector)
Frequency range: 100 MHz to 1.6 GHz.
Input impedance 50Ω.
Attention! Do not apply more than 5V (DC+AC
peak) to this input terminal.
DC (pushbutton)
Selection of AC or DC coupling of the signal