Principas konstrukcija - užspaudimas ampermetras
The core of the transformer is made into a movable opening, and into a clamp, and the movable part is connected to the handle 6, and when the handle is held tightly, the core of the current transformer is open, and the measured intercept current 4 can be placed in the jaws, and the intercept current conductor becomes the primary side coil of the current transformer. Uždaryti the jaws, in the core of the current transformer there is an alternating magnetic flux per the secondary winding of the transformer 5 to produce indukuota current. Ammetras prijungtas į abu galus iš the antrary winding, the current value indicated by its pointer is proportional to the operating current of the interceptor wire clamped into the current value can read directly from the dial to be measured.
Clamp ampermetras naudojimas
First of all, pagal to the type of current to be measured voltage level of the correct choice of clamp ampmeter, the measured line voltage should be lower than the rated voltage of the clamp meter. Measurement of high-voltage line current, should be used with its voltage level in line with the high-voltage clamp ampmeter. Low voltage clamp ampermeter can measure the current in the low-voltage system, can not measure į srovė
Antra, the appearance of the clamp-on ammeter should be properly checked before use, and the insulation of the meter must be check to see if it is good, the shell should be free of damage, and the handle should be clean and dry. If the pointer is not in the zero position, it should be mechaniškai zero. Spaustukas ampermetras žandikauliai turėtų būti sandariai įjungtas, jei the pointer shakeking, can re-open and close the jaws once, if the shakeking still exist, should be carefully check, pay attention to clear the jaws of debris, dirt, and then measured.
As the clamp ampmeter to contact the measured line, so the clamp ampermeter can not measure the current of the bare conductor. When measurement with a high-voltage clamp meter, it should be operated by two people, wearing insulated gloves, standing on insulated mats and not touching other equipment to prevent short-junging or grounding when measurement.
Matavimas
Pirmiausia, naudojant veržliarakčius, juos reikia spausti tvirtai, kad žandikauliai atsidarytų, matuojamas laidas būtų Centre tarp žandikaulių, o tada atlaisvinti veržliarakčius ir leisti žandikauliams užsidaryti tvirtai. Jei ant žandikaulių sujungimo paviršiaus sklinda jokie garsai, jis turėtų būti vėl atidarytas ir uždarytas kartą, o jei garsai vis dar girdimi, sujungimo paviršius turėtų būti tvarkomas, kad matavimas būtų tikslus. Be to, nespauskite dviejų laidų tuo pačiu metu. Po matavimo atidarykite žandikaulius, ištraukite matuojamą laidą ir padėkite bloką į didžiausią srovės bloką arba OFF bloką.
Antra, pagal to the size of the measured current to choose the appropriate range of the clamp-type ampmeter. The selected range should be little larger than the measured current value, if it is impossible to estimate, in order to prevent damage to the clamp ampmeter, it should be measured from the maximum range, and gradually change the gear till the range is appropriate. Tai yra griežtai draudžiama į perjungti the stops of the clamp-on ampmeter during the measurement, and the measured wire should be drawn from the jaws before change the stops when change the stops.
Kai matuojamas srovės dydis, mažesnis nei 5 ampera, siekiant padaryti matavimą tiksliau, kai leidžia sąlygos, matuojamos srovės nešimo laidą galima įdėti į matavimo žnyplės, apvyniojant keletą ratų. Šiuo metu matuojamos vielos faktinė srovės vertė turėtų būti lygi skaitiklio rodmenims, padalintiems iš vielos apvijų skaičiaus žnyplėse.
Measurement should pay attention to all parts of the body and the electrified body to maintain a safe distance, low-voltage system safety distance of 0.1 ~ 0.3 meters. Measurement of high-voltage cable current in each phase, the distance between the cable head line should be more than 300 mm, and good insulation, to be considered patogu to measure before. Stebėti the meter time, pay special attention to keep a safe distance between the head and the energized part, the distance between any part of the human body and the energized body shall not be less than the wholere length of the clamp meter.
Kai matavimas the current of low-voltage fundible fuse or horizontaliai arsured low-voltage busbar, each phase of the fusible fuse or busbar shall be protected and isolated with insulation material before measurement so as not to cause a short-circuit between phases. Measurement is strictly prohibited when one phase of the cable is connected to ground, to prevent the occurrence of ground-breaking explosion due to the low insulation level iš kabelis galva ir pavojus asmeninis saugumas.
Po matavimas
Measurement after the end of the clamp-on ammeter of the clamp-on ammeter, if the general common magneto-electric system clamp-on meter measurement, the indication value and the actual value of the measured will have a great discrepancy, or even no indication, the reason is that the magneto-electric system clamp-on meter of the meter head and the secondary coil of the transformer is connected to the meter head voltage is obtained from the secondary coil. According to the principle of electromagnetic induction can be seen, the mutual inductance electric potential of E2=4.44fWФm, by the public display is not difficult to see, the size of the mutual inductance electric potential is proportional to the frequency. When using this clamp meter to measure the rotor current, due to the rotor on the lower frequency, the voltage obtained on the meter head will be much smaller than the voltage when measuring the same industrial frequency current (because this meter head is designed according to the industrial frequency of AC 50Hz). Sometimes the current is so small that it does not even allow the rectifier element in the head to conduct, so the clamp meter does not indicate, or the indicated value is very different from the actual value.
