Get AN/PSM-4A Multimeter Instruction And Maintenance Manual

Shock hazards can occur if the meter and test leads are not properly maintained. Arc flash can occur if the meter is not properly rated for the voltage, the meter is exposed to transient voltages outside of its operating conditions, or because of defective parts or components.

General Maintenance of Ohmmeter: Digital multimeter is provided with a fuse. Replace it if the ohmmeter is not working. Clean the surface from dust, dirt, grease fungus etc. Remove dust or dirt from terminals with a soft brush.

Misuses of Multimeters One of the most potentially dangerous misuses would be measuring voltage while the model's test probes are in the current terminals, which is something most individuals do by accident. Even though the DMMs fuse offers protection, one shouldn't forget that this protection isn't absolute.

Test Your Probes or Leads Set your multimeter to the ohm meter on the selector knob. Plug the black probe into the common port. Insert the red probe into the jack marked for ohms. Gently tap the red and black tips together. ... Your reading should be 0.5 ohms or less. If your reading is higher than that, replace the probes.

Multimeters should be stored in a dry place where they will not be subject to physical damage. Most multimeters will come with a case in which to store them. This case not only keeps all the pieces together in one place (meter, leads, batteries, magnetic strap etc.)

Using one hand (place the other behind you or in your pocket, or use it to hold the meter), clip a lead onto the first measurement point (preferably not the one that's hot). Then pick up the other lead and hold it (or clip it) to the other reference point. Why do it this way?

Overpowering the digital multimeter can damage the components inside the meter. For example, Figure 2 shows that the maximum voltage input of a 34461A digital multimeter is 1000VDC and 700 VAC. Before turning on or off the connected equipment or the DUT, reduce the signal level to the minimum safety level.

Do not use your test leads if the protective insulation on the leads or probes is cracked or worn. Your fingers may touch the probe conductor, and this might result in a very bad shock. The movement of current from one hand to the other during an electric shock is the most dangerous.