A multimeter, also known as a calibration bench or box is used to test many types of electrical devices for many problems such as broken circuit or shorts. It can be both handheld and bench mounted, so before you set out to buy a calibration instrument, it’s best to know beforehand how you’re going to use it and all the types that exist.
Bench-mounted types tend to be much more accurate than the handheld ones, but a handheld calibration tester is much more convenient for carrying around. So keeping this in mind while also considering what you’ll be using it for, will surely help you narrow down your choices and decide which model and type to pick.
For example, someone working in a garage will probably need the most basic model. A professional on the other hand, will need a much more advanced model that can function and take more accurate measurements. Additionally, it’s of vital importance that the user follows all the necessary procedures to avoid getting himself injured in the process or damaging the device.
Most calibration instruments can measure a wide array of properties including resistance, conductance, frequency and inductance. Some of them can also measure duty cycle and temperature. The most high-end models are capable of measuring decibels, rotations per minute and microamps. However, all calibration instruments are separated into two basic categories – digital and analog.
Digital testers use digital circuits, which means they measure current in discrete increments instead of continuous range of values. The measurements are usually made in analog form, meaning – they have to be converted into digital afterwards. Since it takes some time for the analog readings to be converted into digital, this type of calibration instruments may not be suitable for measuring values that constantly change. They have a battery that powers up the display and tend to be more accurate than their analog counterparts. Most of them are accurate to within half of a %.
This is the more cheaper option, but are also much more difficult to read for newbies. Analog meters were the first type that was developed and they use a needle and a pointed scale to show readings. They’re built around an ammeter which measures current in amperes. They are more suitable than the analog type for measuring values that are subject to constant change. The analog meter transfers electrical energy into mechanic. The most important thing to look for when purchasing an analog meter is its sensitivity. It needs to have at least 20k ohm/V or it may upset the circuit being tested, resulting in false readings.