The digital grounding resistance tester converts direct current to alternating current low frequency constant current by a DC/AC converter, forms a loop through the assisted grounding electrode C and the measured object E, generates an ac voltage drop on the measured object, and is fed via the assisted ground electrode P. Interchanges are amplified by amplifiers, and then displayed through digital detection. The measurement range is 0 to 2Ω, 0 to 20Ω, and 0 to 200Ω. Three different ranges are used to improve the accuracy of the display.
Digital Earth Resistance Tester Test Procedure:
Ground resistance measurement along the ground electrode E (C2, P2) to be measured and the potential probe P1 and current probe C1 are 20 meters apart from each other in a straight line, so that the potential probe is in the middle of E and C, and the probe is inserted into the earth as required .
· Connect the ground resistance instrument terminals E (C2, P2), P1, and C1 to the position of the probe with special wires.
· Turn on the earth resistance tester power switch "ON", select the appropriate gear lightly press the button indicator indicator lights, the value of the meter LCD display is measured ground resistance.
The soil resistivity measurement measures four probes in a straight line in the soil to be measured, and makes the probes have the same pitch, the distance between each pitch is L, and the depth of the probe is required to be L/20 cm, and the wires are respectively Each terminal of C1, P1, P2, and C2 is connected to four probes. If the resistance meter measures resistance R, the soil resistivity is calculated as follows:
Ф = 2πRL Ф - soil resistivity (Ωcm), L-distance between probe and probe (cm), R-resistance reading (Ω)
The soil resistivity measured by this method can be approximated as the average soil resistivity embedded in the area between the probes.
• The probe used for measuring the earth resistance and soil resistivity is generally an aluminum alloy pipe or round steel with a diameter of 25 mm and a length of 0.5 to 1 m.
Ground voltage measurement and measurement wiring as shown in Figure 1, dial out the C1 plug, E, P1 plug retention, starting voltage (EV) file, indicator light, read the meter value is E, P1 AC voltage between ground.
Press the power OFF button after the measurement is completed. The digital ground resistance tester can be automatically turned off.
Taps and dies are tools used to create purpose screw threads, which is called threading. Many are cutting tools; others are forming tools. A tap is used to cut or form the female portion of the mating pair (e.g. a nut). A die is used to cut or form the male portion of the mating pair (e.g. a bolt). The process of cutting or forming threads using a tap is called tapping, whereas the process using a die is called threading.
Using an ordinary tap or die to clean threads generally removes some material, which results in looser, weaker threads. Because of this, machinists generally clean threads with special taps and dies-called chasers-made for that purpose.
Drill And Tap Set,Hand Tap And Die,Cutting Tool Sets,Hand Tap Wrench
Behappy Crafts (suzhou)Co.,Ltd , https://www.jshaoyue.com