How to look at the stop watch, how to look at the mechanical stop watch

There are two types of stop watches, one is an electronic stop watch (digital) and the other is a mechanical stop watch (similar to a clock).

The electronic stop meter reads directly, with minutes on the right, seconds in the middle, and milliseconds on the left.

The mechanical stop watch is a large circle of 30 seconds on the outside, and a minute on the small circle inside, and there are numbers on the inside, so you don't have to worry about not being able to read it.

Stop watch is a commonly used instrument for measuring time intervals. It is timed by controlling the rotation of the hands by using the isochronism of the pendulum. Here's how to stop the meter reading:

1.First minutes and then seconds. If the minute hand is more than 3 minutes and less than 4 minutes, the subdial reading should be 3 minutes; The minute hand has crossed the middle line of 3 and 4 and the reading should be greater than 30 seconds.

2.Readings should be made in relation to the relationship between the minute hand and the middle line of two adjacent minutes. If the minute hand exceeds the reading by more than 30 seconds, but the reading is less than 30 seconds, the reading should be over the reading.

3.Stop meter reading = small circle value + large circle value. For example, a stop meter reads for 3 minutes of seconds, which is seconds.

You can read the data of the stop table based on the preceding method.

Secondly, look at the big circle, or the turntable within 31 to 60 seconds.

If we look at the minute hand in the second figure, it is actually divided into 30 seconds and makes a circle.

Then it's in 1 to 30 seconds Hello, I've already told you.

Let me tell you a little bit more detail.

First of all, the small circle represents the minute, the one, two, and three circles are 0 and 0, respectively, and the large circle represents the second.

The first great circle has 60 turntable numbers, and it already points to the position halfway through the 1 minute, so every 1 second is represented.

Second, third, the numbers on each reel are a bit strange.

The view of the mechanical stop watch is as follows:

1. The mechanical stop watch is composed of two bezels, the large bezel has 30 grids, each grid represents 1s, and 30s after one turn; The small bezel has 15 grids, each grid represents 1min. The small bezel goes 1 square, and the large wheel bezel turns 2 times.

2. When reading, first look at the subdial to determine the number of minutes, and add the seconds of the large dial, for example, the time has passed 2min6s. Let's take a look at the time reading.

3. The subdial represents the time that has passed 2min30s, and the large dial is 6s, adding up to 2min36s. Therefore, when the mechanical stop watch is reading, first look at the subdial, then look at the large dial, and add it up. Sometimes we come across such a dial.

4. We can regard the large dial scale as two circles of scales, when the subdial pointer is in front of the center line, use 2min to increase the small scale of the dial orange plate for 6 s, which is 2min6s; When the subdial hand is behind the center line, use 2min to increase the dial scale by 36s, which is 2min36s.

The large circle corresponds to 30 seconds per revolution of the second hand, so its scale is 0-30 seconds, and the range of every 1 second is 10 divisions (each division is a second).

The stop watch is a watch that is supplemented by a low-frequency balance balance oscillating system through a mainspring and an anchor escapement, and a gear system drives the hands to display minutes and seconds, and is equipped with a special start-stop mechanism.

A common timekeeping tool used in the laboratory is a stop watch (mechanical stop watch and electronic stop watch), which is an instrument that we commonly use in the laboratory. The indexing value of the electronic stop watch can reach the second. When the mechanical stop meter is reading, it is necessary to read out the minutes (small plate:

A revolution is 15 or 60 minutes, there are also 30 minutes, hereby added) and seconds (**: a revolution is 30 or 60s) and add them together.

Stop watch is a commonly used instrument for measuring time intervals. It is timed by controlling the rotation of the hands by using the isochronism of the pendulum. On its front is a large dial with subdials above it.

The second hand rotates along the major dial, and the minute hand rotates along the subdial. The sum of the time indicated by the minute and second hands is the measured time interval. Directly above the watch there is a watch handle, and there is a button on it.

Turn the button and wind it up, this is the power for the stopwatch to move.

Press the button with your thumb and the stopwatch starts the timer; Press the button again, the stopwatch stops moving and takes a reading; Press it again and the stopwatch returns to zero, ready for the next timer.

The most common timekeeping tools used in laboratories are stops (mechanical and electronic), and the exact value of the electronic stops can reach the second. When the mechanical stop meter is reading, it is necessary to read out the minutes (small plate:One revolution is 15 minutes) and seconds (**:

make one turn for 1 minute) and add them together. It has an accurate value of seconds.

Application method: Stop watch is a commonly used measuring time interval instrument. It is timed by controlling the rotation of the hands by using the isochronism of the pendulum. On its front is a large dial with subdials above it.

The second hand rotates along the major dial, and the minute hand rotates along the subdial. The sum of the time indicated by the minute and second hands is the measured time interval. Directly above the watch there is a watch handle, and there is a button on it.

Turn the button and wind it up, this is the power for the stopwatch to move. Press the button with your thumb and the stopwatch starts the timer; Press the button again, the stopwatch stops moving and takes a reading; Press it again and the stopwatch returns to zero, ready for the next timer. (Note:.)

This procedure must be completed before the next timer can be used to use this type of stopwatch. This type of watch cannot be stopped and then restarted to keep a continuous time. In order to solve this problem, some stopwatches are equipped with a button on the left side of the watch handle, and when the watch moves, push this button up, and the watch stops; Push down to continue accumulating timers.

Abbreviation: One tone (zero); Two press (start); Three stops; Fourth Reading.

a) There are various specifications of the stop meter, and they are used in slightly different ways.

The orange peel of the stop watch has a handle at the upper end, which is used to tighten the spring and control the movement and stop of the stop. Before use, wind up, hold the stop watch with your hand when measuring, press the big finger on the handle, press it a little harder, stop the watch immediately move, and then let it bounce back on its own; When you need to stop, you can press it again; The third time again, the second hand and the difference hand spring back to zero. There are also some stops that use different handles or buttons to control the walking posture, stop and reply.

2) Precautions when using the stop meter.

1 Check if the zero point is accurate. If not, the reading should be noted and corrected.

2 Do not fall during the experiment to avoid shock.

3. After the experiment is completed, the stop watch should be allowed to continue to move so that the mainspring is completely relaxed

The first is the range; The second is the graduation value.

We can see that there are two dials on the stop table above, a large dial and a small dial. The subdial has a measuring range of 15 minutes and a graduation value of 30 seconds. The first half (white) represents 0-30 seconds, and the second half (red) represents 31-60 seconds.

The large dial is a refinement of the 30-second section of the subdial. So the range is 30 seconds, and the scale is seconds. Hold and pay attention to the indication of the large dial.

2-4-6-8-10-12-14-16-18-20-22-24-26-28-30 in black, 31-33-35-37-39-41-43-45-47-49-51-53-55-57-59 in red.

Illustrate with examples:

For example, read the subdials first.

2. Re-read the large dial, the hands are in the first half of the (white) degree part, so the reading range of the large dial is 0-30 seconds. The subdial has been determined to be 0-30 seconds, and the hands are observed to be in the 2-4 range, reading seconds.

3. Final reading, comprehensive reading of large and small dials: 0 minutes + seconds = seconds.

Stop meter reading = minutes of small plate + second reading of **.

As shown in the image above, the reading is 3 minutes and seconds.

As you can see in the image above, the reading is 2 minutes and 36 seconds.

Small plates: Usually available in 30 and 60 scales. For the 30-scale type, each grid represents a minute, and for the 60-scale type, each grid represents a minute.

**:** Each lap represents 30s, a total of 60 large scales, and there are 5 small scales between every two large scales, so each large scale represents, and each small scale represents, which is also the accuracy of the stop.

for the reason. Read the reading of the small market first, its unit is minutes, look at the above indication to know that each minute is divided into the first half minute and the second half minute, pay attention to see which half minute it points to.

Then read the reading of **, which is measured in seconds, 0-30s if it is the first half minute, and 31-60s if it is the second half minute.