Verification standard of electronic crane scale

How to verify the electronic crane scale?

Verification of electronic crane scales shall be carried out in accordance with the following procedures in accordance with the verification regulations of JJG539-1997 "Digital Indicating Scales".

(A) appearance inspection

According to the appearance requirements of the verification regulations of JJG539-1997 "Digital Indicating Scale", the appearance inspection of the electronic crane scale is performed. Those who meet the requirements are qualified, otherwise they are disqualified.

(2) Verification of measurement performance

Before the measurement performance verification, the load should be pre-loaded to the weighing or safety load.

(1) Zero test

① No scale with zero tracking device or automatic zero setting

First set the crane scale to the zero position, and then measure the sum of the standard weight (0.1e) added to the previous graduation value from zero to zero, and calculate the zero point error according to the error formula.

② Scale with zero tracking and automatic zero setting device

First, the indication is adjusted outside the automatic zero setting and zero tracking range, such as adding a weight load of 10 e, and then finding the flicker point, and calculating the zero error according to the zero error formula. The zero error requirement is not greater than 0.25e.

③ Zeroing before loading

For non-automatic zero-setting scales, first place the standard weight of O.5e on the carrier of the electronic crane scale, and then adjust the electronic crane scale to flicker between zero and the previous division value, then remove the standard Weight and get the zero center.

(2) Weighing verification

The weighing verification of the electronic crane scale should include the following weighing points:

①Minimum weighing.

② Allowable error change points: such as 500e and 2000e of towel standard scale; 50e and 200e of standard scale.

③ l / 2 weighing.

① Weighing.

It is required that the error of each load is not greater than the allowable error of the corresponding load.

(3) Rotation test

For the same hanging electronic crane scale. First apply 80% of the weighing weight to the hook of the electronic crane scale, then rotate 360 ° clockwise and record the display value every 90 °; then rotate 360 ° counterclockwise, also every 90 ° Record the display once. It is required that the error of each time shall not be greater than the error of the corresponding load to be qualified. Otherwise, it will be disqualified.

(1) Discrimination test

The discrimination test of the electronic crane scale is carried out in three places: minimum weighing, 1/2 weighing and weighing.

The specific test method is: first add a minimum weight to the electronic crane scale, and then add 10 0.1e standard weights. Then remove O.1 from the electronic crane scale in turn. Until the displayed value decreases by an actual division value, then reduce the small weight by 0.1r. Add it again, and slowly add a 1.4e weight, the display value of the electronic crane scale has increased by two more d. It means that the discrimination is qualified. Otherwise it will be disqualified.

In the same way, the above method is used to re-verify the 1/2 scale and the discriminating power at the scale.

(5) Repeatability test

The repeatability test of the electronic crane scale should be performed at two places of the 1/2 scale and the scale. Requires no less than 3 tests per group. Before each test. The electronic crane scale should be adjusted to zero first, and the electronic crane scale with automatic zero setting or zero tracking device should be kept in operation.

The repeatable test error of each group shall not exceed the allowable error under this weighing. And the difference between any two indications of each group must not exceed the allowable error of the weighing point.

(6) Overload test

Use more than 20% of the weight to apply to the hook of the electronic crane scale. After 15 minutes of static lifting, all parts of the electronic crane scale should be intact and intact. At the same time, when overload is required, the indicator should have functions such as alarm and overload not to display.

When the full load is unloaded, the empty scale display value is checked back, and the error of the indicated value does not exceed the allowable error.

(Three) data processing

(1) Calculated based on the original verification data, the qualified person will be issued a verification certificate and pasted the verification mark. Those who fail the test will be notified of the result of the test and stop using it.

(2) The longest test period is one year. Frequent use can shorten the test period appropriately.

What are the verification items of the electronic pricing scale?

According to the provisions of the verification regulations of JJG539-1997 "Digital Indicating Scales", the verification items of electronic pricing scales are:

1. Visual inspection.

2. Zero check.

3. Weighing test.

4. Eccentric load test.

5. Discrimination test.

6. Repeatability test.