Hameg Instruments LCR-Bridge HM8118 Handbuch Seite 45

as this field is open, the actual measured value of the DUT (=
Device Under Test) may be set as the reference by pressing
the TRIG button.
5.1.15 Constant voltage CST V:
At this point the constant voltage (AC) may be turned on/off.
In some cases a test may require the use of a specific mea-
surement voltage due to the source impedance which is not
available together with the normal source impedance of the
respective range . In order to achieve this, a constant voltage
(CST V) may be switched in with the menu function SETUP.
For all measurements with BIAS voltage or current
the constant voltage (CST V) must be turned on!
The menu function SETUP is selected by pressing the SELECT
3
button . Use the arrow buttons
6
to set the parameter CST V to ON. This will set the source
impedance to 25 Ω. For all components with impedances >25 Ω
the voltage will remain nearly constant. In order to prevent
overloading the bridge the selected range may automatically
change, depending on the impedance of the component. Ope-
rating in constant voltage mode decreases the accuracy by 2.
The following table lists the impedance ranges for constant
voltage operation (CST V ON):
Measurement Source
range Impedance
1 25 Ω
2 25 Ω
3 25 Ω
4 25 Ω
5 25 Ω
6 25 Ω
The following table lists the impedance ranges when the constant
voltage mode is switched off (CST V OFF):
Measurement Impedance of the
range component
1 to 2 Z >
2 to 3 Z > 400.00 Ω
3 to 4 Z >
4 to 5 Z > 100.00 kΩ
5 to 6 Z >
2 to 1 Z <
3 to 2 Z < 324.0 Ω
4 to 3 Z <
5 to 4 Z < 81.0 kΩ
6 to 5 Z <
There may be conditions which cause an OVERRANGE display.
This may happen if both constant voltage and manual operation
is selected. In order to sidestep this problem choose manually
a higher range or switch to automatic mode (AUTO).
5.2 Menu function CORR
The submenu of CORR allows the selection of:
5.2.1 Calibration OPEN:
At this point the open circuit calibration can be turned on/off (pro-
cedure description at chapter 6.1).
5.2.2 Calibration SHORT:
At this point the calibration with shorted terminals can be turned
on/off (procedure description at chapter 6.2).
Die GATE-LED leuchtet während der gesamten Dauer einer
Messung. Dies entspricht der gewählten Torzeit und einer
Synchronisierungszeit.
3 REMOTE (LED und Taste)
Die REMOTE–LED leuchtet, sobald das Gerät über die Schnitt-
stelle angesprochen wird. Um zur manuellen Betriebsart
zurückzukehren, ist die REMOTE-Taste zu drücken.
4 Display (LCD-Anzeige)
Anzeige des Messergebnisses und verschiedener Zusatzin-
formationen
5 ESC (Taste)
Escape-Taste in der Menüsteuerung
6 ENTER (Taste)
Enter-Taste in der Menüsteuerung
SELECT (Taste)
7
Menüaufruf bzw. Auswahl eines Menüpunkts
7
8    (Tasten) and the knob
Pfeiltasten zur Menüsteuerung und Parametereinstellung
9 Drehgeber
Drehknopf zur Parametereinstellung
10 GATE TIME (Taste)
Einstellung der GATE-Zeit
11 LEVEL B (Taste)
Impedance of the
Einstellung des Triggerlevels von Kanal B
component
12 LEVEL A (Taste)
10.0 µΩ — 3.0 Ω
Einstellung des Triggerlevels von Kanal A
3.0 Ω — 100.0 Ω
100.0 Ω — 1.6 kΩ
13 16 1 : 10 (Taste)
1.6 kΩ — 25.0 kΩ
Eingangssignalabschwächer, Gesamtabschwächung 100-fach
25.0 kΩ — 2.0 MΩ
2.0 MΩ — 100,0 MΩ
8
Änderungen vorbehalten
3.33 Ω
6,67 kΩ
2.22 MΩ
2.7 Ω
5.4 kΩ
1,8 MΩ
S e t t i n g o f i n s t r u m e n t p a r a m e t e r s
Fig. 5.3: Display of the menu function CORR
5.2.3 Calibration LOAD:
At this point the calibration with a known load impedance can
be turned on/off. For any measurements with load impedance
calibration the desired function must be selected manually
28
by pressing of the buttons
chap. 6.3).
5.2.4 NUM:
Here, one of 6 available LOAD impedances 0 to 5 can be selected.
5.2.5 Frequency FRQ:
The measuring frequency of the load impedance (LOAD) may
be selected from 20 Hz to 200 kHz.
5.2.6 Function FUNC:
At this point the reference values for the load impedances
LOADM and LOADS can be selected. The following functions
are available:
Ls-Q, Lp-Q,
Lp-Rp, Cs-D,
Cs-Rs, Cp-Rp,
Rp-Q, Z-Q,
R-X G-B
5.2.7 Reference value LOADM for the main
measurement value:
A measurement result may be stored in memory LOADM as
the reference value for the load impedance LOAD. The availa-
ble units are, depending on the parameter FUNC: H, mH, µH,
nH, F, mF, µF, nF, pF, Ω, mΩ, kΩ, MΩ, or S, kS, mS, µS, nS, pS.
5.2.8 Reference value LOADS for the second
measurement value:
Here a measurement result may be stored in memory LOADS
as the reference for the load impedance LOAD. The available
units are, depending on the function FUNC: Ω, mΩ, kΩ, MΩ, S,
kS, mS, µS, nS, pS or °.
Remark!
When using the calibration with a load, values must
be entered in both reference memories (e.g. if an
ohmic resistance is used for LOADM its value will
be stored in LOADM , and „0" in LOADS.)
The parameters LOADM and LOADS can be used, if it is difficult
to calibrate a test fixture or if it is connected via long leads. In
such case it is not possible to realize a full open/short calibration
because the actual circuit of the fixture can not be compensated
by a simple equivalent circuit provided in the LCR bridge.
The bridge can hence remain in an uncalibrated state. By using
a known impedance at the measuring frequency the user can
compensate for the resulting measurement error.
17 50 Ω (Taste)
Zuschalten eines 50 Ω-Widerstands z
sung bei 50 Ω-Systemen
18 LP 50 kHz (Taste)
Tiefpassfilter zur Vermeidung unerwü
bei niederfrequenten Signalen
19 23 TRIG (LEDs) Triggerindikatoren
20 22 INPUT A, INPUT B (BNC–Buchse
Messsignaleingänge DC-200 MH
21 AUTO TRIG (Taste)
Aktivierung des Auto-Triggers. Die Ta
wenn die automatische Triggerung a
INPUT C (SMA-Buchse)
24
Messsignaleingang 100 MHz – 3 GH
RESET · V
25
Taste mit Doppelfunktion:
1. Durch Drücken dieser Taste wird
unterbrochen, die Anzeige gelöscht
39
... (procedure description at
gestartet.
2. Bei Einstellung des Triggerlevels mit
der eingegebene Wert mit der Einheit
26 TRIG · GHz/s (Taste)
Taste mit Doppelfunktion:
1. Auslösen einer Messung im ARME
2. Bei Einstellung der Gatetime mit de
eingegebene Wert mit der Einheit Se
27 HOLD · mV (Taste)
Taste mit Doppelfunktion:
1. Durch Drücken dieser Taste wird
angezeigte Messwert eingefroren.
Ls-Rs,
Cp-D,
Rs-Q,
Y-Q,
Subject to change without notice
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