Nowadays, digital measuring instruments have become the mainstream, and there is a trend to replace analog meters. Compared with analog instruments, digital meters have high sensitivity, high accuracy, clear display, strong overload capability, easy to carry, and simpler to use. Take the VC9802 digital multimeter as an example to briefly introduce its usage and precautions. (1) How to use a Before use, you should carefully read the relevant instruction manual, familiar with the role of power switch, range switch, jack, special socket. bSet the power switch to the ON position. c AC and DC voltage measurement: If necessary, set the range switch to the appropriate range of DCV (DC) or ACV (AC), insert the red test pen into the V/Ω hole, insert the black test lead into the COM hole, and connect the test lead to the line under test. The reading is displayed. d AC and DC current measurement: Set the range switch to the appropriate range of DCA (DC) or ACA (AC), insert the red test pen into the mA hole (<200mA) or 10A hole (>200mA), and insert the black test lead into the COM hole. Connect the multimeter in series with the circuit under test. When measuring DC, the digital multimeter can automatically display the polarity. Measurement of e resistance: Turn the range switch to the appropriate range of Ω, insert the red test lead into the V/Ω hole, and insert the black test lead into the COM hole. If the measured resistance value exceeds the maximum value of the selected range, the multimeter will display "1" and a higher range should be selected. When measuring resistance, the red test pen is positive and the black test pen is negative, which is the opposite of the pointer multimeter. Therefore, when measuring polar components such as transistors and electrolytic capacitors, you must pay attention to the polarity of the test leads. (2). Precautions for use a If you cannot estimate the magnitude of the measured voltage or current in advance, you should first dial the measurement to the highest range and then gradually reduce the range to the appropriate position. After the measurement is completed, the range switch should be turned to the highest voltage and the power should be turned off. b When the scale is full, the meter only displays the number “1†in the highest position, and the other bits disappear. In this case, a higher range should be selected. c When measuring voltage, the digital multimeter should be connected in parallel with the circuit under test. When measuring current, it should be connected in series with the circuit under test. It is not necessary to consider positive and negative polarity when measuring DC. d When the AC voltage is misused to measure the DC voltage, or the DC voltage is used to measure the AC voltage, the display will show “000â€, or the number on the low position will jump. e It is forbidden to change the range when measuring high voltage (above 220V) or high current (above 0.5A) to prevent arcing and burn switch contacts. f When “ â€, “BATT†or “LOW BAT†is displayed, it indicates that the battery voltage is lower than the operating voltage. This is a spy hidden camera with different lens angles, complete functions and a wide range of applications. Spy Hidden Camera,hidden video camera,spy camera,hidden spy camera,hidden cameras Jingjiang Gisen Technology Co.,Ltd , https://www.jsgisentec.com
First we look at the angle, there are 90 degrees, 120 degrees, 140 degrees, 180 degrees and so on.
Looking at the function, we have 1080p, 720P and other pixels, spy camera with audio and night vision, as well as mobile additional measurement function.
Finally, look at our application, we use a wide range of scenarios, study, work, police use, home use and so on.
December 24, 2022