Electronic scales are easy to break down and nee∞&d to be repaired for damage caused by overl☆♦oading

At present, the use of electroniββ c scales is very convenient. With the continu↓Ω££ous supply of production costs and ₹£ prices, electronic scales manufacturersπ∞♠ are increasingly popular in production, trade "★ "and other aspects, and are deepl≤"y loved by the majority of use∑ε₽δrs. However, because the eβ♠<₽lectronic scales use sensors as weighiαδ≤ng components, it is difficult to ©α™maintain the electronic scales af≈£ter failure.

Sensor is an important part of electronic scλ≥ale. At the same time, sensor i‌&s a relatively easy part to damage in e×♣lectronic scale. It is easy to cause s∑©←ensor overload damage because of improper use a¥↔ nd weighing objects beyond the me☆→±asurement range of electronic ₩±scale. At the same time, in ©₽order to reduce costs, some manufacturers of el₩↓'€ectronic scales use the sensor β'with low overload capacity, and the↑™ design of preventing ♦<♦ sensor overload is too simple, which →δ objectively causes the electronic scales easy ε ←¶to break down and damage due to overload and ne>↓¶eds to be repaired.

Fault Maintenance and Judgm<‍¶ent Scheme of Electronic Scale

(1) By measuring the input and ou∏λ tput resistance of the se•‍>nsor, the quality of t€↕λ✘he sensor can be judged. ←π®When inspecting the sensor, the connection line≤←≠ of the sensor should be judged first. For the♥∑♦ sensor connected to the circuit, a simplΩε e method can be used: turγ∏n on the power supply of the electronic ✔✔₽scale, then turn on, use t÷±he universal meter DC voltage, ↓↕the negative pole grounding an∞φ"d the positive pole to me$♣ βasure the four connec₹÷☆tion lines of the sensor respectively"↑<™. The voltage is zero (grounding). Itβ©9;s V-1. The highest voltage is₽• V+, and the half voltage is S+and S-1¥<.

(2) By measuring the zero o£™utput signal of the sensor, the quality of the s​β ¶ensor can be judged. Because the internal cirφ✔cuit structure of the sensor is a br↔ &↔idge, the output signal val≤®♣λue of the two signal terminals (s + aε←₩↕nd S 1) should be 0 m V in the αory without load. But in fa®↑δct, due to the fabrication proce✔✘"ss of the sensor, the zero output si✔¥gnal can not be completely zero. According to th€¥e national standard, the zero output signal α can not be greater than ₩£the + I% FS output of the sensor. For example, iε§↔f the sensitivity of a sensor is 2.φ←'00 mV/V, the input vol★σ÷tage of the circuit is 1 O V, the maxi✘ mum output voltage of the sen±↓sor is 2 mV, and V(sensitiv&≠✘ity)*10 v(input voltage)=2 O mV, the zero output ₽♠ ₩signal should not exceed -I-1%x 20®γ₩> mV=i-0.2 mV.

3. Short circuit of eΩ>♣×lectronic scales; in'<​♠ the actual detection ≤♥≈process, for electronic scales that can not>εΩ start normally, two signal terminals §™≤(s + and s 1) can also be shor≤≠≈t-circuit directly with a♥↕π  metal tweezers, and then start ≠>★up. If the electronic scales can start normally a&§nd display zero posit✔←♥γion, it can also be  § ★basically determined that the sensor is over↓ ∑≥loaded and damaged. The principle is to bal₩£σ¶ance the voltage of the two ©∑βsignal terminals by direct short circuit, so tha≤™♦t the program considers the sensoδ★≤r to be normal, and then through the self-φλchecking program.

4. replacement method. For sensors tha∏↑t can not be determined by the above methods¥±₹ , they can be replaced. Connect a sensor w§α€←ith similar sensitivity and resistance ™ ≈to the circuit. If the electronic scale φ≠​÷can start normally and react to loading&∏, it can also determine the damage o‍∞♣f the original sensor. However, because theγ★∏ data recorded by differe✘ nt electronic scales during calibration ar>∏e different, the measured values displayed by tγαhe transducers are incorrect. When r☆∞eplacing the sensor, it should be noted th∑¥at if the model specifications of the se£↔•nsor are different, it ¶£π is not necessary to re-calibrate or calib↓‌rate it, otherwise the original prog←β&₽ram data may be lost a★φnd can not be recovered.

Maintenance scheme o↑₽f electronic scales s¶∑ensor overload, resulting in damage can be divε "↑ided into two categories to a c ®★<ertain extent

(1) The elastomer is severely damaged. The ela£↔§₽stomer has been deformed directly fr→‌×σom the appearance, the intern↑≥al resistance strain gauge may have been broken,✔∞↔δ and the output resistance value is↓≥©↑ infinite. In this case, the sensor♦&σ₹ has no repair value, so​γ★ it is recommended to replace it.

(2) The elastomer is not seriously def‍≠$ormed, but the output resistance≥δ£​ is unbalanced, or the zero ou≠σtput value is too large∑<. This kind of situation can be repair☆₽ed by simple methods. According to the act×&ual maintenance experience, sensor overload cau™​ Ωsed irreparable damage is not much.

The following describes the maintenance methods ≠<of electronic scales, mainly for tλ∑he second situation.

(1) re calibration. The ↑♥€electronic scale can be re-calibrated‍↕ if it can start normally, but it shows o∏↕verload when it is loaded •✔₩to or near full range load. Because modern e→®>lectronic scales generally have int∞εernal calibration procedures in softwar©εe design, when the indication error is small"​¶↔, the electronic scales can be re-£★Ω∑calibrated according to the specifi₩ σcations or the technical information provided by→Ω♦♥ the manufacturer, which ca∑™n often make the electronic scales return to noλ₩'←rmal.

(2) To adjust the zero voltage of ↑♣¥≈the circuit, because the zero o×↔ε≥utput of the strain sensor is diffe↓‌♣↔rent and unstable, many electr☆φεonic scales will design a zero-adjusting cir←∞cuit. There are generally two ways o∑≤ε♥f adjustment.

First, the use of adju→Ω→stable potentiometers; second,§≥ the use of jumper switches. ≤> It's OK to adjust the pφβγotentiometer or jumper ↑"directly during maintenance.

By understanding the structure principle o♣σσ✘f resistance strain sens∞☆φ'or and using the above several maintenan"♦ce methods, the state of se‌÷€↕nsor can be checked quickly, the dam‌₽γage of sensor can be judged, and the fault Ω∏can be eliminated effectively.