Which test pen is connected to the positive pole when measuring DC voltage with a pointer multimeter
With a pointer multimeter, when measuring DC voltage, you should first check whether the multimeter is good or bad, the measurement is accurate, and the pointer is sensitive or not. Insert the red test lead into the jack marked with 10.V/Ω", insert the black test lead into a C0M" jack, adjust the gear knob to any resistance gear, short-circuit the red and black test leads, and the pointer deflects to the right to about zero , and then turn the zero adjustment knob to adjust the pointer to zero. If the pointer is at the infinity position and the short-circuited test lead does not swing to the right, check whether the fuse in the watch is blown. If the fuse is normal, replace the battery in the watch. When the resistance gear is short-circuited and the pointer of the test pen cannot be adjusted to zero, it is also necessary to replace the battery in the watch.
When measuring DC voltage, if the voltage value is known, you can directly adjust the knob to the corresponding gear of DCV. It is worth mentioning that the closer the gear is to the measured voltage, the more accurate the measured value is. For example, 1.5v chooses 2.5v gear, 12v24v chooses 50v gear, etc. If you don’t know the voltage to be measured, you should choose the highest gear and measure sequentially. And lower the gear until the measured voltage is close to the selected gear. Do not measure high voltage at a low gear, which will deflect the pointer and easily damage the multimeter. When measuring, place the multimeter as horizontally as possible to avoid affecting the accuracy of the measured value.
When measuring the DC voltage, the red test lead must be connected to the positive pole and the black test lead to the negative pole, otherwise the needle will be deflected and the multimeter will be easily damaged. The battery is known to be 9v, so select the 10v range.
When reading the value, you should look at the second scale line marked ACV.DCV on the meter head, count the scale lines from left to right, and the obtained value is the difference between the actual scale line reading multiplied by the gear value divided by the total scale line, is the final value. As shown in the picture above, 47X (10÷50) 2 9.4Ⅴ is a new battery just bought, and the measured value is slightly higher than the marked value, indicating that the performance of the battery is very good!
