GT4508A electric meter modification and calibration experiment instrument Use and experimental instructions I. Overview Pointer ammeters, digital voltmeters, multimeters are widely used in various electrical measurement applications. Simple pointer galvanometers or single-range digital voltmeters can only be used to measure small currents and voltages, so it must be The meter can be modified to be used in various measurement fields. The instrument is equipped with a pointer galvanometer, a standard voltmeter ammeter, an adjustable DC stabilized power supply, a decimal resistance box, special wires and other components. It can complete the modification of ammeter, voltmeter, ohmmeter and other experiments without other accessories. Through experiments, the ability of users to use electric meters and use electric meters can be improved. Second, the main technical parameters 1. The pointer type is modified: the range is 100μA, the internal resistance is about 2.1kΩ, and the accuracy is 1.5; 2, resistance: R1 adjustment range 0 ~ 111110Ω, R2 adjustment range 0 ~ 11111.10Ω, accuracy 0.1%; RN adjustment range 0.1Ω～1MΩ, 8 stops, accuracy 0.05%; R4 selection range is 9MΩ, 900kΩ, 90kΩ, 10kΩ, accuracy 0.05%. 3, digital modified table: 0 ~ ± 200 mV, three and a half digital display, accuracy ± 0.5%, optional decimal point position; 4, adjustable voltage regulator source: output range 0 ~ 2V, 0 ~ 20V two range, output current 20mA, stability 0.1% / min; 5, adjustable constant current source: according to RN in 0.1Ω ~ 1MΩ different ranges, the output is 1A ~ 0.1μA, open circuit voltage: about 5V, stability 0.1% / min; 6, power supply: AC 220V ± 10%, 50Hz. 7, need additional equipment: one and four and a half digital multimeter. Third, the instructions for use The panel of the instrument is shown in Figure 1. Figure 1 Schematic diagram of the panel The adjustable DC voltage regulator is divided into two ranges of 2V and 20V. The voltage output is selected by the “voltage selection switch†to adjust the voltage required for the “voltage adjustment†potentiometer. The indication of the pointer voltmeter is also correspondingly divided. It is two ranges of 2V and 20V. Its output current is limited to 200mA. Adjustable steady current source I: A positive terminal is connected to a current terminal of RX, and its negative terminal is internally connected to a current terminal of RN. See the panel diagram. According to RN in different ranges of 0.1Ω～1MΩ, the output is in 1A～ 0.1μA, open circuit voltage: about 5V, stability 0.1% / min; in use, according to different measurement objects, the current can be adjusted to the value of "1000" by the "current fine adjustment" knob. The measured digital voltmeter has a measurement range of 0 to ±200 mV. Please do not exceed this range. When converting the voltmeter and ammeter, input from both "+" and "-"; when modifying the digital resistance meter, RN The voltage at the RX terminal is internally connected to the V-number table through the switch conversion, and then connected to the converted digital meter input terminal by a short circuit. R1 and R2 are a series of decimal resistance boxes. In order to reduce the influence of lead resistance, R2 resistors are provided with 3 terminals. When the resistance is less than 11.1Ω, please connect 0~11.10; more than 11.1Ω For the resistance value, please connect both ends of 0~11110. Note that the power used must not exceed 0.25W, and the current should not exceed the current value defined by the power. The allowable value of this current is different in different resistance gears. RN is the shunt resistor when modifying the digital ammeter. Note that its power should not exceed 0.25W, and the current should not exceed the current value defined by the power. Its resistance is internally connected to the four terminals of the RN. R4 is used to modify the voltage divider resistance of the digital voltmeter, the power should not exceed 0.25W, please use as needed. RG can be used to artificially change the internal resistance of the pointer meter. It can be used to study the change of the modification parameters when the internal resistance of the meter head is different. The power consumption should not exceed 0.25W. The RX terminal is used for externally connected resistance, and there is no connection resistance inside. Therefore, the four terminals of RX are not connected internally, and should be connected by external wiring. Note: For the measured resistance less than 10Ω, please use four Line method connection. The measured resistance greater than 100Ω can be measured by the two-terminal method. At this time, the potential end and the current end of the same side of RX are short-circuited and short-circuited, and the two ends are measured. Fourth, maintenance and warranty 1. The instrument should be used correctly according to the experimental requirements. 2. Turn off the power switch after use. If it is not used for a long time, please dial the power plug. 3. The instrument should be stored in an environment free of corrosive substances and kept dry to prevent corrosion. 4. Under the conditions of use of the user, the warranty period of the product is 12 months. If the warranty period is exceeded, the manufacturer will still provide good service. Cosmetic Brush Storage Box,Beauty Makeup Brush Storage Box,Cosmetic Storage Box SZ CHENGYANG BEAUTY TOOLS CO.,LTD , https://www.cyfootfile.com