Πολύμετρο συντήρηση μέθοδος
1. Do not connect to DC voltage higher than 1000V or AC RMS voltage higher than 700V;
2. Do not connect the voltage source when the function switch is in the Ω and position;
3. Please do not use the watch when the battery is not installed or the back cover is not tighted.
1. Οπτική επιθεώρηση
If it is found such as disconnection, desoldering, short circuit, broken fuse tube, burnt out components, etc., you can touch the temperature rise of the battery, resistors, transistors, and integrated blocks. You can refer to the circuit diagram to find out the reason for the abnormal temperature rise.
2. Τάση μέτρηση μέθοδος
By measuring if the working voltage of each key point is normal, you can fast find out the fault point, such as measuring the working voltage and reference voltage of the A/D converter.
3. βραχυκύκλωμα μέθοδος
%0αΗ μέθοδος του ελέγχου ο A/D μετατροπέας γενικά υιοθετεί το βραχυκύκλωμα μέθοδος, που είναι συχνά χρησιμοποιείται σε επισκευή αδύναμο και μικροηλεκτρικό όργανα.
4. Κύκλωμα θραύση μέθοδος
%0αΑποσύνδεση το ύποπτο μέρος από το σύνολο μηχάνημα ή μονάδα κύκλωμα. Αν το σφάλμα εξαφανίζεται%2γ αυτό σημαίνει αυτό το σφάλμα είναι στο το αποσυνδεδεμένο κύκλωμα. αυτό μέθοδος είναι κυρίως κατάλληλο για το περίπτωση του α βραχυκυκλώματος σε το κύκλωμα.
5. μέτρηση στοιχείο μέθοδος
Πότε το σφάλμα έχει μειωθεί σε ένα ή πολλά συστατικά, it μπορεί να μετρηθεί online ή εκτός σύνδεσης. Εάν απαραίτητο, αντικαταστήσει αυτό με a καλό στοιχείο. Εάν το σφάλμα εξαφανιστεί, it σημαίνει ότι το συστατικό είναι σπασμένο.
Επιλογή αρχή από πολύμετρο
1. The reading accuracy of the pointer meter is poor, but the process of the pointer swing is more intuitive, and its swing speed range can sometimes objectively reflect the size of the measured (such as measuring the slight jitter); the reading of the digital meter is intuitive, but the process of digital change looks messy and not easy to watch;
2. There are generally two batteries in the pointer meter, one is low voltage 1.5V, and the other is high voltage 9V or 15V. Resistance file, the output current of the test pen of the pointer meter is much larger than that of the digital meter, the speaker can make a loud "da" sound with the R×1Ω file, and the light-emitting diode (LED) can even be lit with the R×10kΩ file;
3. In the voltage range, the internal resistance of the pointer meter is relatively small compared with the digital meter, and the measurement accuracy is relatively poor. In some high-voltage and micro-current occasions, it is even impossible to measure precisely, επειδή its internal resistance will affect the circuit under test (such as When measuring the acceleration stage voltage of a TV picture tube, the measured value will be much lower than the actual value), the internal resistance of the voltage file of the digital meter is very large, at least in the megohm level, which has little influence on the circuit under test, but the output σύνθετη αντίσταση is extremely high It is ευαίσθητο to the influence of induced voltage, and the measured data may be false in some occasions with strong electromagnetic interference;
4. In short, pointer meters are suitable for the measurement of analog circuits with relatively high current and high voltage, such as TV sets and audio amplifiers. It is suitable for digital meters in the measurement of low-voltage and low-current digital circuits, such as BP machines, mobile phones, etc. It is not absolute, and pointer tables and digital tables can be selected according to the situation.
