VOM clock is an indispensable gadget for {hardware} restore individuals specifically and electronics basically. To assist newcomers know find out how to measure and use watches. The article on find out how to use the VOM clock and find out how to use it would make it easier to considerably.
VOM watches have quite a lot of costs from 100k – 1 million. Costly watches have extra features equivalent to frequency measurement, Mosfet check…. As a result of there are not any circumstances to make use of, my article solely mentions this metallic watch that solely prices about 120k.
1. Form
_VOM clock makes use of 2 main 1.5v batteries and 1 giant 9v battery. Contains needle, show glass, knob to zero, scale adjustment, 2 black and purple measuring wires.
_ Symbols on VOM
Ω : Ohm ( ohm ) : unit of resistance.
V : Volt (volt) : unit of voltage.
A : Amp : unit of present.
DC : Used to measure DC voltage.
AC : Measure AC voltage.
DCV: DC voltage.
ACV: AC voltage.
The VOM meter has the next two fundamental parameters:
Measuring stage: On VOM, there are 4 levels together with Ω, ACV, DCV, Ampere.
Scale: Within the measuring section, there are numerous scales. For instance: Section measuring DCV (volts) contains the size: 0.5V, 2.5V, 10V, 50V… When measuring we must always alter the size accordingly for extra correct parameters. If measuring 3.3V supply, we alter the size greater and the closest is the 10V scale.
2. Use of VOM clock.
VOM meter contains the next fundamental makes use of:
Measure DC and AC voltages.
Measure continuity to see if the circuits are related. Form of like measuring a wire to see if it breaks. Alter the clock to the X1 ohm scale. If the clock goes to zero, the circuit is open, if it would not, the wire is damaged.
Measure the studying of the resistor.
Verify the discharge of the capacitor.
Measure amperage, this operate can be hardly ever used.
3. Learn how to measure with VOM meter.
+ Measure voltage:
DCV . DC voltage measurement
Flip the knob to the DCV scale to succeed in the suitable scale with the worth to be examined.
The purple rod clamps onto the (+) terminal of the item to be measured.
The black rod clamps onto the (-) terminal of the item to be measured.
Learn the measurement outcomes on the DCV show arc that matches the size. For instance, when measuring a voltage of 10v, we alter the size to 10v then learn the end result and show DCV 10V.
Be aware: When measuring, you need to decide the right unfavorable and optimistic poles.
Measure AC voltage ACV
Change the knob to the ACV scale set on the 250 ACV scale, clamp 2 check results in the two ends to be measured.
Learn the measurement outcomes on the ACV measurement worth show body.
Necessary notice: AC voltage could be very harmful, so when measuring, it’s mandatory to concentrate to make sure security. Completely don’t put the size of resistance or present measurement into the AC voltage. If left mistaken, it will likely be broken, burn the resistor within the meter.
+ Measure resistance
Alter the X1 scale to hug and brief the purple and black rods collectively. Then flip the calibration knob to the right zero place for a extra correct measurement.
Alter the Ohm scale to match the resistance to be measured: together with the X1, X10, X1 Kohm and 10 Kohm scales.
Place the purple and black rods within the place of the resistance to be measured. Then take a look at the worth on the displayed arc Ω for the X1 ohm scale. For different scales it’s essential to take the worth displayed on arc X (multiply ) by the size. For instance, we alter the clock at X10 ohm scale and the studying on the show is 15, the resistance worth is = 15 x 10 = 150 Ohm.
If when measuring the needle solely inched up slightly or almost the entire needle, we have to alter the suitable scale to make the measurement extra correct.
+ Measure the discharge of capacitors : Capacitors and ceramic capacitors
Measuring capacitors: Capacitors are giant capacitors which might be plentiful on the mainboard and polarized + and – . Capacitors are hardly ever shorted, most of them are dry capacitors, so the discharge cost will not be good. To measure the cost discharge of the capacitor, observe these steps.
Take away the capacitor you need to measure from the mainboard, and use a brand new capacitor with the identical voltage and capacitance parameters to match.
Set the clock to the X1 or X10 scale. Proceed to place the black rod on the – pole, the purple rod on the – pole, learn the parameter. Then reverse the probe and browse the studying.
Just like the above measurement with the brand new capacitor, and conduct comparability.
If measuring 2 capacitors, the clock palms are equal and return, it is nonetheless good. In distinction, the previous capacitor has a decrease needle than the brand new capacitor is dry.
Measuring ceramic capacitors: Ceramic capacitors are small capacitors (stick capacitors) and usually are not polarized. Ceramic capacitors are sometimes shorted, detected.
Take away the suspect capacitor from the motherboard. Set the clock to X1K or X10K scale. Place the purple and black rods on the 2 ends of the capacitor, learn the show and reverse the probe.
If the clock palms go up after which right down to the preliminary place, the capacitor is nice. If the needle goes up however doesn’t return to its authentic place, the capacitor is detected. If the needle goes to 0Ω and doesn’t return, it’s brief.
There’s additionally a operate of measuring amperage, resulting from little use, I didn’t point out it. These are
Pin 9 volt có tác dụng gì. Sao gỡ nó ra đồng hồ vẫn đo bình thường. Cám ơn