Use And Maintenance of Weighing Display Instrument

Since the 1980s, China's weighing instrument industry has actively referred to relevant international suggestions and approached foreign advanced technical standards. At the same time, due to the rapid development of electronic technology and the popularization and application of electronic computers, weighing display instruments have many functions such as storage, operation processing and classification recording, which make them widely used in large weighing instruments, small weighing instruments Quantitative weighing instrument and other fields. The correct use and maintenance of the weighing display instrument can not only make the weighing display instrument play a full role, but also create higher economic benefits through scientific management.
1. Type of weighing display instrument
(1) According to the weighing status, it is divided into static weighing display instrument and dynamic weighing display instrument. Static weighing display instrument is used for electronic platform scale, electronic pricing scale, truck scale, etc. dynamic weighing display instrument is used for belt scale, dynamic track scale, dynamic truck scale, etc.
(2) It is divided into: batching scale, quantitative packaging scale, electronic hanging scale, electronic truck scale, electronic desk scale, belt scale, dynamic track scale weighing display instrument and other special weighing display instruments.
(3) According to the weighing method, it is divided into non automatic weighing instrument and automatic weighing instrument. The weighing display instrument of non automatic weighing instrument is used for electronic platform scale, electronic pricing scale, truck scale, etc. the weighing display instrument of automatic weighing instrument is used for electronic sorting scale, belt scale, dynamic track scale, dynamic truck scale, etc.
2. Working principle of weighing display instrument
After the elastomer of the load cell is subjected to gravity, the Wheatstone bridge composed of resistance strain gauge generates a sensor analog signal of about 0mV ~ 25mV (the size of the analog signal is directly proportional to the size of the sensor subjected to gravity). The analog signal amplifies the sensor analog signal to about 0V ~ 3V through the signal amplifier, and then passes through the analog-to-digital conversion circuit (A / D) convert the analog signal into the corresponding internal code digital signal, and finally process the data through the CPU. At the same time, it receives the operation instructions input by the processing keyboard, displays the scale through the weighing display instrument and transmits the data over a long distance, so as to realize data storage, data call, system control with data, etc.
3. Use of weighing display instrument
(1) Installation of weighing display instrument
Before installation, commissioning and operation, carefully read the operation manual of the weighing display instrument to fully understand the installation, commissioning and specific operation procedures. A good service environment can ensure the normal operation of the weighing display instrument and prolong the service life of the instrument.
● working power supply voltage: 187ac ~ 220ac
● working power frequency: 49hz ~ 51hz
● working environment temperature: 0 ℃ ~ 40 ℃
● humidity of working environment: the relative humidity is less than 95%, without condensation.
If the DC voltage supplied by the rechargeable DC battery of the weighing display instrument does not meet the normal working requirements of the instrument, the weighing display instrument shall have undervoltage prompt or alarm.
The weighing display instrument shall not be used in the harsh environment with high moisture, dust, hydrochloric acid and alkali content, and must be far away from the strong magnetic field, otherwise the weighing display instrument, computer, printer and other equipment will not work normally.
(2) Connection between weighing display instrument and sensor
According to the lead instructions provided by the manufacturer of the load cell, when welding rs233 nine core socket with an electric soldering iron, each wiring terminal of + e, + s, - E, - s, 〨, + in and - in must be carefully welded to prevent false welding and short circuit.
(3) Connection between weighing display instrument and printer
You can use the 25 core parallel output printing cable provided by the weighing display instrument or attached to the printer. After connecting the weighing display instrument with the printer, tighten the screws with a special screwdriver to prevent connection failure due to loose connection.
(4) Connection between weighing display instrument and large screen
Through the pin of rs233 plug, the signal is 20mA constant current current loop signal, which is connected with the large screen with binary serial output.
(5) Connection between weighing display instrument and computer
The communication data can be divided into instruction mode and continuous mode. The connection with the computer is defined according to pins RXD, TXD and GND.
(6) Debugging of weighing display instrument
After the weighing display instrument, other relevant equipment and power supply are installed according to the technical requirements, it shall timely apply to the local metrological verification department for detection, detect the indication accuracy, repeatability, stability and partial load performance of the weighing system, and adjust the indication accuracy according to the metrological verification regulations to maintain its good metrological performance.
4. Use of weighing display instrument
(1) The operator of weighing display instrument shall be familiar with measurement technology, laws, regulations and work responsibilities.
(2) The operator of the weighing display instrument must receive professional and systematic training and be familiar with the internal structure, performance, working principle and correct operating procedures of the weighing display instrument and other related equipment.
(3) The operator of the weighing display instrument shall be familiar with the main functions of the weighing display instrument and the significance of technical parameters, and be able to deal with common faults in time to ensure the normal use of the weighing system.
(4) The operator of the weighing display instrument shall carefully fill in the use record of the weighing display instrument.
5. Maintenance of weighing display instrument
(1) Routine maintenance
Maintain indoor hygiene, check whether the working voltage, temperature and humidity meet the technical requirements, and wipe the weighing display instrument, computer, printer, large screen, regulated power supply and other related equipment with semi dry cotton cloth. It is forbidden to use solvent chemicals (such as benzene, alkali acid and nitro) to clean the instrument to prevent corrosion of weighing display instrument, computer, printer and other parts.
For the daily maintenance of the micro printer equipped with the weighing display instrument, the printing paper shall be protected from moisture, edge warping and unevenness, otherwise it is easy to cause the printer paper jam, thus affecting the service life of the printer. When the printer is not working, ensure that there is printing paper between the drum and the printing needle, otherwise the service life of the printing needle will be affected. The surface of the Micro Printer shall be cleaned frequently to reduce external dust, small particles, etc. entering the interior of the micro printer. The steps for cleaning the printer are as follows: ① turn off the power supply of the weighing system, turn on the weighing display instrument, and unplug the power supply plug of the micro printer; ② Open the upper cover of the micro printer; ③ Remove the paper loader, remove the dust and dirt inside with a small brush, and then cover the upper cover; ④ Wipe the outside of the micro printer with a clean semi dry cotton cloth, then connect the power supply plug of the micro printer, close the weighing display instrument, tighten the screw, and connect the instrument power again.
(2) Precautions for operating procedures
During daily cleaning, the power supply must be turned off and the power plug must be pulled out of the socket, otherwise it will lead to electric shock accident or damage to the weighing system, making it unable to work normally. Be careful not to unplug the serial port with power, otherwise the components of the serial port will be damaged.
After the weighing system is powered on and preheated for 15 minutes, carefully check whether the weighing display instrument, computer, printer, large screen, regulated power supply and other relevant equipment are in normal working state, and conduct simulation operation to check whether the weighing system is in normal working state.
Electric welding or other strong current operation on relevant equipment of weighing system is strictly prohibited. In the thunderstorm season, the power supply of the weighing system must be cut off and the work must be stopped to ensure the safety of staff and related equipment.

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