What are the symbols on a mulitmeter electricity trading jobs

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A – usually "Amps"; the full term is Ampere and it is a measurement of the current flowing through the circuit. You usually measure amps by hooking the meter into the circuit you are measuring, in series. Make absolutely sure that the meter is designed and set up to handle the measurement you are attempting to take. Measuring a mains plug usually requires a very expensive multimeter, while your garden-variety electronics multimeter would be fried.

mA – Milliamps; 1/1000 of an amp. Electronic circuits usually carry mA of current, while mains plugs carry full amps. To reinforce the point; using a meter designed for milliamps to check things like home electrical wiring will send many thousands of times more current through the meter than it is designed to handle, and you will fry your meter.

V/mV – Voltage. This is a measure of electrical potential, or the difference in the charge carried by the circuit at different points in the circuit. The most practical use of voltage metering is to detect the usage of electrical power by different nodes in the electrical circuit. Voltage metering is generally done by placing the meter in parallel with two points in the electrical circuit. DO NOT connect a meter set up to check volts in "series" with an electrical circuit; again, you’ll fry your meter.

~/- – When you see a wavy line used with amp or voltage settings, that means the setting is for use in an A/C circuit. Most simple household electrical devices like lamps, refrigerators, washers/dryers, etc use alternating current, where the current passes through the circuit in one way, then the other, and this changes very rapidly. Analog audio signals are also represented as A/C. By contrast, a solid straight line, usually with a dashed line underneath it, is a DC circuit. Most electronics use direct current, where the current flows in only one direction.

Omega symbol (horseshoe) – Resistance, measured in ohms. Resistance is simply the property of a circuit to inhibit the flow of electrons through it in general. Impedance, in simplest terms, is resistance of a circuit to alternating current; simple resistance will provide impedance, but there are other properties of A/C circuits that impede the flow of electricity. Remember the formula I=V/R; Current I, in amperes, flowing through a simple circuit is equal to the circuit’s voltage, in volts, divided by its resistance in ohms.

W = Watts. The watt is the unit of electrical power, or a circuit’s ability to do work. 1W = 1V x 1A. A 120V, 10A household electrical circuit (common in the U.S. for most non-appliance circuits) can supply 1200W of electrical power. Power over a given amount of time equals the work done by electricity, commonly measured in the U.S. in kW/h, the equivalent of 1000W of power being used for one hour. Wattage can be confusing, especially in audio equipment, because of the various ways it can be measured or estimated.

pF/uF/mF/F, usually with a -|(- symbol – Capacitance, in pico/micro/milli/farads. Capacitance is the property of an electrical component to "soak up" electrons when placed in a circuit. In an A/C circuit, capacitance increases impedance. Capacitors, or electrical components designed to soak up current, are used heavily in electronics to provide a constant flow of electricity, and in audio circuits for an interesting property; the impedance a capacitor provides to a circuit depends on the frequency of the current direction-switching; high frequencies have low impedance through a capacitor, while low frequencies have a high impedance. EQ/tone controls and crossovers make use of this characteristic.

-|<- symbol – Diode. A diode is simply an electrical node with a defined input and output. Most diodes used in electrical circuits have a "one-way" property; when placed in an A/C circuit, they only allow current to flow in one direction, presenting near-infinite resistance to flow in the other direction. There are numerous applications for diodes in electronics. Multimeters for electronics use commonly include a "diode checking" mode that will determine that a diode does inhibit flow properly, and in which direction the flow is inhibited.

Thanks keith, that explains it alot then. My friend told me about measuring the voltage comeing through the system and out the speaker binding post to see how much voltage is going through to the speakers so you can see how much power is getting to you speakers. He also said about that way being a good way of using an an extra powerful amplifier to power your speakers, I think he said twice the power if I remember right and then using a voltage meter to make sure you’re definately giving your speakers enough voltage while leaving headroom. I read about it on the internet so I asked him and he told me a bit about it. He didn’t tell me how to use the voltage meter because he was in a rush.I’ve got a pair of electrovoice tx2152 speakers. I got them after reading good things about the tour x series on a few forums. the amplifier i’ve just bought lasy week to power them is a crown xls5000 and I want to make sure i’m getting 1,000 watts into them and use the rest of the power as headroom. My friend told me that 1,000 watts equates to 63.5 volts so thats what I need to see on a decent quality true rms multimeter in order to know that i’m getting the 1,000 watts into the electrovoice speakers. He said that the rest of the power of the xls5000 is headroom meaning I can have the level on my system lower to achieve the same spl.