Calibration method of vertical and horizontal burning test apparatus for wire and cable

The wire and cable vertical and horizontal burning test apparatus is in accordance with UL 1581, UL 13, UL 444, UL 1655 VW-1 and CSA FT-1 standards. Test the burning resistance of various wire and cable insulation coating materials, printed circuit board materials, IC insulators and other organic materials. At present, the inspection rooms of wire and cable enterprises are equipped with this Testing Equipment.

1. Working principle of vertical and horizontal burning test apparatus for wire and cable

Vertical and horizontal burning test apparatus for wire and cable is composed of two parts: a burning test chamber and a control cabinet. The main function of the wire and cable vertical and horizontal burning test instrument is to generate a standard flame for testing, and to accommodate the burning space of the flame-retardant cable, the attached temperature measurement method, time measurement and other functions. The control cabinet is a device that generates a current that is more than 5 times the rated working current of the cable. According to the measurement requirements can generate 10A ~ 5000A working current.

2. Standard equipment for calibration

To calibrate the mine cable load burning test apparatus, the following standard equipment should be available:

(1) A steel tape measure (0-5) m.

(2) One vernier caliper (0-150) mm.

(3) One standard electric transformer with a range of (0~100)A, (0~500)A, (0~1000)A, (0~5000)A, or one multi-range standard transformer; One ammeter above class 0.2.

(4) Thermocouple verification device, measuring range (0～1300)℃.

(5) Secondary instrument calibrator: It can output K-type indexing standard signal.

(6) Electronic stopwatch: 0.01 second division value.

3. Calibrate the environmental conditions

Ambient temperature: (-15～45)℃ Relative humidity: (30～80)%RH

4. Calibration items and calibration methods

4.1 Measurement of the dimensions of the burning test machine

Use a steel tape and a vernier caliper to measure the size of the mine cable load burning test chamber.

(1) The box size of the burning testing apparatus should meet the following requirements (the allowable error is 2mm).

4.2 Working current, temperature instrument, time parameter measurement

(1) Working current measurement

For working current measurement, select the appropriate cable according to the measured range, pass the cable through the primary coil of the transformer, then connect the cable to the current output terminal of the control box, and connect the transformer to the standard instrument. Select 5 points evenly on the measured output range, which must include the large current value.

Slowly raise the current to each test point, and then read the standard indication value, the detected indication value minus the standard indication value is the error of the output current, and the allowable error is 5%.

In the current measurement, it must be noted that when performing large-scale verification, due to the extremely large current value, the connection between the cable and the connector must be reliably connected, and attention should be paid to the connector when increasing the current. If there is light and smoke, the experiment must be stopped immediately and the connection checked.

(2) Temperature instrument measurement

Use the secondary instrument calibrator to verify the thermometer according to the requirements of JJG617-1996 "Digital Temperature Indicator Verification Regulations". According to JJG351-1996 "Basic Metal Thermocouple Verification Regulations", after the thermocouple is removed from the device, the thermocouple verification device is used for verification, and the verification temperature range is (0 ~ 300) ℃.

(3) Time measurement

The timing device on the testing machine and the electronic stopwatch start timing at the same time, and when the time is over, stop timing at the same time. The time measurement point is 5 minutes, 10 minutes, and 20 minutes, and 3 points are selected for measurement, and each point is measured 3 times. According to the measurement result, the time measured by the electronic stopwatch is subtracted from the time set by the timing device, which is the time measurement error, and the allowable error is 2s'.

5. Calibration result expression

After the calibration is completed, a calibration certificate will be issued, and the calibration data will be filled in according to the measurement data.

6. Recalibration interval

The recalibration interval is determined by the user according to the usage situation, and it is recommended to be 12 months.

The wire and cable vertical and horizontal combustion test machine is suitable for the combustion resistance test of various wire and cable insulation coating materials, printed circuit board materials, IC insulators and other organic materials. During the test, put the test piece on the top of the flame, burn for 15 seconds, extinguish for 15 seconds, repeat 5 times and check the burning condition of the test piece, you can set the burning. Turn off time and repetition times, and can be operated automatically. If you need to know more about vertical and horizontal burning test apparatus for wires and cables, please consult Zonsky Instruments.