×òîáû ïîìåíÿòü ÿçûê
èíòåðôåéñà ïðîãðàììû, íàæìèòå
êíîïêó ñ ñèíèì êðóæêîì ðÿäîì ñ
ýìáëåìîé ÐÌ. çàòåì âûéäèòå èç ïðîãðàììû, è
âîéäèòå â íåå ñíîâà.
Oscilloscope.
The general information.
Switching of inputs.
The circuit of the external device. Calibration.
The analysis of a spectrum.
Two-coordinate mode (dynamic characteriograph).
The generator. Additional
adjustment.
The Capacity - meter.
The Voltage -
Frequency Caracteriograph.
Switch off the speakers !
The built - in virtual Capacity - meter allows
to estimate electrical capacity in limits from several pF up to
50 mkF. The device shows the
measured value of capacity, the nearest value from a standard
line for condensers, and also intermediate results used at
account. The device automatically chooses range,
establishing the optimum frequency of the generator. C - meter is convenient for sorting and
selection of condensers. In updatings can be used in other
purposes, for example with capacitor gauges at measurement of not
electrical sizes, for detection of breakages in cables.
The principle of capacity measurement is illustrated
by the circuit and formula placed below.
From an output of Sound Card the sine wave acts on a
chain consisting of the examinee condenser Cx and the resistor R.
The Sound Card inputs are connected for the measurement of
voltage: V1 - total, V2 - on the resistor R. The voltage U2 at
known value R is the information about a current through a chain.
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Put any condenser Cx, and you will see on the screen of the scope shift of phases between a total voltage and current through the chain.. |
The method, realized in C-
meter, thus, can be defined as the method of the ammeter -
voltmeter for a complex circuit.
Remember: a capacity of your body influences
result of the measurement, therefore remove your hands after the
connection of the condenser.
The establishing of the size R (R3 ') in the
program is carried out as follows. Press
the R3' button on the form of C - meter, type
value, kOm, then press Enter. At the definition of R value is
desirable to take into account ADC entrance resistance. For
example, if it is 12 kOm, with R =1,5 kOm you should establish
12*1,5 / (12+1,5) =1,33 kOm.
At the first activation of C - meter the message
"Change the input " can appear. Then at the presence of
the window of C - meter press the button Mixer. On its form specify a Line input. It is
necessary for making it once, so that the program "has
remembered" that input as necessary to use with C - meter
and specified it, if you switched inputs. And the last adjustment. Disconnect any Cx, press the
button 0. The program "will
remember" an initial capacity of connected wires and jacks,
and will subtract it from the current results.
Recommended oscilloscope input sampling
frequency for C - meter function is 48 or 44,1 kHz. It is
possible to establish more frequency at the measurement of small
values of the capacity.
Do not switch needlessly the display speed (panel X).
At the start of C - meter the minimal speed is
established. For its work
is necessary, that the reception buffer (the scope screen)
contained some periods of a signal, including on the lowest
frequencies of the measurement (5 Hz).
The generator output voltage depends on a position of
the main volume regulator (on the Windows tasks panel ). If it is
unsufficient for work of the C - meter, the message Volume? will appear, so you should add the volume. Also it is
possible to restore positions of all regulators pressing button Mixer, then Restore.
C - meter claims
the high requirements to Sound Card and its driver. The card
should support the full duplex stereo mode. It is preferable to
work under Win XP, 2000, NT. With Win 98 program is efficient,
but requires more resources of the system.