How To Make Measurements; Mesure De Tensions Alternatives; Resistance Measurement - Conrad M-3890DT Mode D'emploi

How to make measurements

Attention:
Never exceed the maximum admissible input ratings in the over-
voltage category II (domestic and industrial ranges). The frequen-
cy of the alternating-current ratings must not exceed 500 Hz. Do
not touch any circuits or circuit components if the voltages
applied there are higher than 25 V A.C.rms or 35 V D.C. There is a
danger to your life. Before making measurements, check the mea-
suring lines connected for damage, e.g. cuts, cracks, or squeezed
points. Remove defective measuring lines immediately and repla-
ce them with new ones; defective measuring lines must never be
used again. There is a danger to your life.
a) Resistance measurement
Attention:
Make sure all circuit elements, circuits, and structural parts which need mea-
suring and other objects to be measured are surely under no voltage.
For resistance measurements and acoustic continuity tests, proceed as follo-
ws:
- Connect the black measuring line to the COM socket
(14) and the red measuring line to the VΩ socket (13)
until these come to flatly lie on the measuring instru-
ment.
- Set the range selector switch (8) to its position
and choose an appropriate measuring range.
- Check the measuring lines for continuity by connec-
ting the two measuring tips to each other. As a result,
a resistance value of abt. 0 ohms should adjust itself.
- The instantaneous value measured will be shown in
the main display and, at a time lag of 1second, the
right-hand sub-display as well.(pseudo-hold function).
- Now, connect the two measuring tips to the object under measurement. The value
measured will be signalled in the main display (25) unless the object under measu-
rement is of the high-resistance type or is interrupted.
Note:
Whenever making a resistance measurement make sure that
the measuring points which you contact with the measuring tips
for measurement be free from dirt, oil, solderable lacquer or the
like. Such circumstances could corrupt the results found by
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e) Mesure de tensions alternatives
Attention !
Ne dépassez en aucun cas les grandeurs d'entrée maximales, ne
les dépassez non plus lors de la mesure de tensions continues
superposées (p. ex. tension d'ondulation). Valeurs maxi : 750 V
ACrms. Ne touchez jamais aux circuits ou aux composants de cir-
cuits présentant des valeurs de tension supérieures à 25 V AC rms
ou 35 V DC.
Marche à suivre pour la mesure de tensions alternatives:
- Raccordez le câble de mesure noir à la borne COM (14)
et le câble rouge à la borne VW (13) et veillez à ce que
les deux soient collés à l'instrument de mesure.
- Mettez le commutateur de sélection de plage (8) en
position V
- Appuyez sur la touche DC/AC (7) pour passer à la plage
AC.
- Puis, raccordez les deux pointes de mesure à l'objet à
mesurer (générateur, circuit, etc.).
- La valeur acquise actuelle s'affiche alors à l'écran principal (25). Le sous-écran
droit (23) indique la fréquence de la tension alternative jusqu'à une valeur de 0,5
kHz au maximum (kilo-hertz = 500 Hertz). Le sous-écran gauche (22) indique la
tension en valeur "dB" (= décibel, 1 mW à 600 ohms).
La gamme de tensions alternatives « V~ » possède une résistance d'entrée d'env. 10
Mohm.
f)Mesure de fréquences
Attention!
Respectez impérativement les grandeurs d'entrée maximales ! Ne
touchez jamais aux circuits ou aux composants de circuits pré-
sentant des valeurs de tension supérieures à 25 V AC rms ou 35 V
DC.
.
o
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