Jan 2, 2014 - Https://www.jaycar.com.au/medias/sys_master/images/838/QM1500-manualMain.pdf.

Using a multimeter This guide starts off with the basics of a meter, proceeds to give a thorough specification for our example meter, then explains how to make measurements, and finishes up with some hints and notes. The example meter that we are demonstrating is typical of many economical digital multimeters that you can purchase, this guide will be useful for all these meters. This guide is concentrating on how to use your multimeter. It all came about, frankly, when we started giving away free multimeters to our design clients - and we realised there was no easy instruction manual for a meter - all that was supplied was a list of (sometimes non-sensical) warnings, and a specification list.

Admittedly we have a specification list here, but we tell you to ignore it if it does not make sense, and we have reduced the warnings to the three that we think really matter. We can supply the meter direct - but our costs are a little higher than the big retailers.

Recently the same meter has availble only in a dark grey colour case. There is also a cheaper version in a plain rectangular case with no rubber holster - great for students, or a second meter. We charge $9 to mail out these meters within Australia - (email for a quote if you want it sent overseas, but honestly it probably isn't worth it, we get charged about $40+ here in Australia to ship anything internationally). Model: Warnings Do not rotate the dial while the meter is connected to a circuit - you may rotate it through a current range, short circuiting the probes and damaging either the meter or the circuit. 3% patch meaning. Respect the circuitry you are working on - If you touch exposed metal, or cause a short circuit, or connect to high voltage, you may expose yourself to hazard - or damage the circuit or your meter. Measuring the short circuit current of a battery or power supply is usually not safe - it is likely to damage the meter or battery and possibly cause the battery to overheat so much that it may be dangerous. You should read all the other important warnings in the instructions that come with your meter, you may even find, somewhere, the author's favourite comical mis-translated warning: 'Do not run the equipment under water or in water shower for fun or any other reason'.

Testing batteries As tersely explained to the left, a battery can be tested, seperately, using a multimeter - but is best tested (supplying power) in the equipment. This is difficult for most people. An alternative is to buy a purpose built battery tester: This is just a meter with a resistor to draw power from the battery, so it is tested under load, as it should be. A simple cheap battery tester is (For - thank you for your help) 1.5V Batteries - A Fresh battery reads 1.56V, A battery is perhaps half used at 1.35V, and is pretty dead by the time it reaches 1.1V.

(Matching figures for 9V: Full = 9.36V, Half = 8.1V, Dead = 6.6V). However, not every item is the same, and some equipment needs a battery with low internal impedance. The amount of current a battery can deliver is not reliably reflected by its open circuit terminal voltage.

The best way to check, if in doubt, is to measure battery voltage while the equipment is running. Lead acid batteries - A 12V lead acid battery generally measures 13.4 to 14V while on charge. When off charge, a full battery will be up at about 12.8V, a discharged battery at about 11V. If a lead acid battery is in the range of 6-8V it is probably in pretty bad shape, and over discharged, or with a shorted cell. Spavner dlya stalker zov pripyati dezertir 2 full.

A shorted cell makes a 12V battery pretty much useless. Lithium Ion batteries - Lithium Ion batteries are the newer type of rechargeable battery.

When fully charged the voltage rises to 4.2V, and at the end of charge the voltage falls to 3.0V - or sometimes down to 2.7V depending on the product. However, these batteries need to be treated with caution. Use only the proper charger, do not short circuit, and do not open them - Lithium incinerates on contact with water. If allowed to completely discharge these batteries are irreversibly damaged. Despite what manufacturers may tell you, these batteries are like any other - they will last 500-1000 charge/discharge cycles if treated well, and that is all - then they need replacement. The older type of rechargeable battery is Nickel Metal Hydride (NiMh) and Nickel Cadmium (NiCd).

These cells are often the same physical size as 1.5V batteries, but a slightly lower voltage: 1.25V when charged, 0.9V when discharged. These batteries are about twice the weight of LiIons for the same capacity. NiCd and NiMh batteries tend to self-discharge over time, sometimes lasting only a few weeks between charges, whether or not they are used. A good example being older NiCd cordless drills - they always seemed to have a discharged battery when you really need them! You cannot easily replace NiCd batteries with LiIon as they are different voltages - you need to replace the whole product, and in cordless drills the batteries are not accessible in any case. There are LSD (Low Self Discharge) NiMh and NiCd batteries available that largely alleviate this problem, the leading brand is Sanyo Eneloop. Elements/Heaters - The resistance of a heater can be calculated by first finding its rated current, and then finding its resistance using ohms law.