The scale in the inspection and inspection of goods need to check what key content, what test need to be carried out, these contents hope to help you!

When it comes to the scale, we will not feel strange, in life to measure the weight is very practical, common electronic kitchen scale, electronic human scale and mechanical human scale

, then the scale in the inspection and inspection of goods need to check what key content, what test need to be carried out, these contents hope to help you!

1. Working principle

When the object is placed on the scale, the pressure is applied to the sensor, which degenerates and thus changes the impedance. At the same time, a change in the excitation voltage is used to output a simulated signal of change. The signal is amplified by the amplifier circuit and output to the analog-to-digital converter. Converted into a digital signal for easy processing and output to the CPU operation control. The CPU outputs this result to the display according to keyboard commands and programs. Until this result is displayed.

2. Classification of weights

In the inspection of goods we commonly have electronic kitchen scale, electronic human scale, and mechanical human scale

3. Main composition

1) Weight sensor 2) Amplifier circuit 3) filter circuit 4) analog-to-digital converter 5) CPU 6) power supply circuit 7) Key 8) housing 9) mechanism 10) Scale plate

Step 4 Test

1) Packaging inspection

(1) Outer/inner box inspection

(2) Color box/blister package inspection

(3) accessories and other inspection

(4) Whether the contents of packaging materials, including instructions, warranty cards and service cards, are consistent with those of the products

2) Safety test

(1) Whether there are sharp edges and points, whether the battery leakage

3) Appearance inspection

(1) Product confirmation inspection

Check whether the products including accessories are consistent with the samples, specifications, orders, color box pictures and contents, instructions, etc provided by the customer.

(2) Appearance inspection

4) Mechanical inspection

(1) Check with hand patting machine: check whether there is any foreign body or loose assembly in the product

(2) Assembly inspection: whether the assembly gap of each part of the accessories is too large, the wrong parts are installed, the accessories are too loose or tight, etc.

(3) Check the battery box and battery door

: After loading the battery, then cover the battery door, pat the machine with your hand, the product should not malfunction. (If the battery is installed in the product, and the customer requires electric insulation protection film, we should check whether this film can play the role of electric insulation protection)

(3) Use a feeler to check whether the foot pad is uneven

Place the product on the glass to see if it shakes, measure the value with a feeler and record it

5) Routine function check

(1)On/Off switch 3 times the product should have the original function

(2) Accuracy test

a. Generally weigh three weights (if the customer has requirements, according to the customer's requirements, if not, generally ask to weigh 10%, 50%, and 90% of the mass of three points)

b. Accuracy requirements (according to customer's requirements if requested, if not, generally require kitchen scale +/-0. 5%, human scale ±1%)

(3)LCD display function check (all strokes should be able to display, no missing strokes, etc.)

(4) All kinds of switches should function normally

(5) Display the weight of the scale and check the automatic shutdown function

(6) Check the weight unit selector switch (Kg, Oz, Lb, etc.)

(7) Peeling function check (for kitchen scale)

Put 1KG weight code on the product and press the "Zero" button.

The product should display '0'. And then add the code,

The product should show the weight added later (i.e. the peel weight).

(8) Overweight function indicator check

(According to the instructions, if the overweight normal code is placed on the product, the product LCD should have overweight display)

(9) '0' adjusting knob function check (suitable for mechanical human scale)

(Adjust the '0' knob, the pointer should be able to indicate '0' and the knob should not be stuck and other undesirable phenomena)

(10) Automatic '0' reset function check (suitable for mechanical human scale)

(Remove the weight on the product, and the pointer of the product should return to the position of '0', and the pointer should not be stuck)

(11) Check other functions mentioned in the specification

6) Special data and measurement items

(1) Security: None

(2) Performance test

a. Measure the battery voltage

Use a multimeter to check that the battery voltage exceeds the nominal voltage.

b. Standby current test

Use a multimeter to check the standby current and record the parameters.

(Connect the multimeter in series to the power supply loop of the product, and the standby current is the current when the device is started and the product is not operated)

c. Check the low-voltage display function

(Low voltage display should be consistent with guest standard or instruction manual)

d. Inspection of large weighing range

(The large weighing range should be consistent with the customer's standard, color box, manual)

e. Resolution check

(The product resolution should be consistent with the customer's standard, color box, manual)

f. Repeated weighing error check

(Use 50% of the nominal large weight to weigh it in the same position of the product for 3 times, and record the change of the weight for 3 times, which should be no more than 1 resolution unit)

g. Check for weighing error of one or both feet (for human scale)

(Weigh the product with one foot or two feet - choose the weight close to the full weight, compare the change of the weight, should not be more than 1 resolution unit)

h. Internal process and main components inspection

(3) Size inspection

a. Scan the bar code

Scan the bar code three times with the scanner

The bar code must be readable and the scanner display should be consistent with the number printed on the bar code.

b. Check the size and weight of outgoing cartons

Measure the length x width x height of the product or measure against the product specifications. If the product specifications are not provided, record the data in the report.

c. Measurement of external dimensions of the product

If the product or package size is not mentioned in the guest's specifications then this test is not suitable.

d. Transportation test

(a) Drop test of outgoing carton (this test is not suitable if not requested by the customer).

Common defects and problems

1. The outer box wheat printing is not good

2. Wrinkled corner of color box

3. Bad printing of the word 'PLEASE' on the plastic bag

4. Dirt diameter in the mirror :0.3mm

5. There is a dent on the back of the product shell. The diameter is 1.5mm

6. Bowl surface scratches (length 15mm)

7. The gong wire is not tight