How to measure the resistance of ZJ2811C?

1) Familiarize yourself with the meaning of the symbols on the dial and the main functions of each knob and selector switch.

2) Carry out mechanical zeroing.

3) According to the type and size to be measured, select the gear and range of the transfer switch, and find the corresponding scale mark.

4) Select the location of the pen jack.

5) Measuring voltage: When measuring voltage (or current), it is necessary to choose a good range, if you use a small range to measure a large voltage, there will be a danger of burning the meter.

Multimeter. Narrow pass; If a large range is used to measure small voltages, the pointer deflection is too small to read. The range should be selected so that the pointer is deflected to about 2 3 of the full scale as much as possible.

If it is not clear in advance the size of the voltage to be measured, you should first select the highest range, and then gradually reduce it to the appropriate range.

A AC voltage measurement: a transfer switch of the multimeter is placed in the AC and DC voltage block, and the other transfer switch is placed in the appropriate range of the AC voltage, and the two meter pens of the multimeter can be connected in parallel with the circuit or load under test.

B DC voltage measurement: a transfer switch of the multimeter is placed in the AC and DC voltage block, and the other transfer switch is placed in the appropriate range of DC voltage, and the "+" meter pen (red table pen) is connected to the high potential, and the "-meter pen (black table pen) is connected to the low potential, that is, the current flows in from the "+" meter pen and flows out from the "-" meter pen. If the pen is reversed, the needle will be deflected in the opposite direction, and it is easy to bend the needle.

6) Current measurement: When measuring DC current, one transfer switch of the multimeter is placed in the DC current block, and the other transfer switch is placed in the appropriate range of 50UA to 500MA, and the range selection and reading method of the current is the same as the voltage. When measuring, the circuit must be disconnected first, and then the multimeter must be connected in series to the circuit under test in the direction of the current from "+" to "-", that is, the current flows in from the red pen and flows out from the black pen.

If the multimeter is mistakenly connected in parallel with the load, the internal resistance of the meter head is very small, which will cause a short circuit and burn the meter. Here's how it is read:

Actual Value Indicates Range Full Bias.

7) Measuring resistance: When measuring resistance with a multimeter, the following methods should be followed:

a. Mechanical zeroing. Before use, the pointer positioning screw should be adjusted to make the current indication zero to avoid unnecessary errors.

b. Select the appropriate magnification gear. The scale mark of the multimeter ohmic block is uneven, so the magnification block should be selected so that the pointer stays in the thinner part of the scale mark, and the closer the pointer is to the middle of the scale, the more accurate the reading. In general, the pointer should be pointed between 1 3 2 3 on the scale.

c ohm zeroing. Before measuring the resistance, the two pens should be shorted and the "ohmic (electrical) zero knob" should be adjusted at the same time so that the pointer is just pointing to the zero position to the right of the ohmic tick mark. If the pointer cannot be adjusted to the zero position, it means that the battery voltage is insufficient or there is a problem inside the meter.

And every time you change the magnification gear, you have to zero the ohms again to ensure the accuracy of the measurement.

dReading: The reading of the meter head is multiplied by the magnification, which is the resistance value of the measured resistance.

Earlier, we summarized the two more important electrical experiments of electrical experiments: measuring the volt-ampere characteristic curve of small bulbs, measuring the electromotive force of the power supply and internal resistance. Today, we continue to refine the relevant content of the electrical experiment. In this chapter, we introduce 5 methods of measuring resistance, the overall difficulty is small, and you need to pay attention.

1. Summary of five methods for measuring resistance.

It mainly includes the following five methods, among which the semi-bias method is the majority.

How to measure the resistance of 2811C? This can be measured with a resistance meter, and buying a car with a resistor, that is, using a shake meter to remove from office is measured with a stopwatch.

If you measure the resistance, you can use a universal meter, which is still very convenient, and her accuracy is still very high.

When measuring with a voltmeter, resistance is the safest and most secure.

In the case of the car mat, you can measure the electrons according to the normal procedure, and if the electrons are powerful, they should not be divided into electrons.

You can measure it, but you need to have a measurement tool for it.

It's very simple, just make a connection now and you can make a measurement.

Hey, if you say this, you should find my professional equipment to do this.

How to measure the resistance of JSC, you should go to a professional place to test it, and see some information about the resistance.

Analysis: The question is whether there are pores, according to the fact that the density of pores is less than the density of copper, the volume of the model is calculated, and the mass of the same volume of copper is compared with the quality of the model, if the mass of the model is small, there are pores, and if it is equal, there are no pores. According to the title:

There is no such thing as a large model mass.

Solution: Let the model volume be v: then.

v=24；24 >175, i.e., the mass of the model is less than the mass of the same volume of copper.

A: This casting has pores!

Wood mold volume = 12 500 =

Casting density = 175. 7〈8900

So it's hollow.

The unit did not write forgive me.

It means that the calorific value is 5500 kcal and the ash is divided into 13 kinetic coal. s is the sulfur content. v is volatile.