There are two measurement systems are analog systems and digital systems. Analog systems related to information and analog data. The analog signal in the form of continuous functions, for example in a temperature indication is shown by the scale, the needle pointer on skalameter, or the appointment of an electronic scale. Digital systems related to information and digital data. Digital numeric designation is a number of discrete and discontinuous pulse is related to time.
Designation display of voltage or current of digital meters in the form of numbers without having to read from the meter scale. Transfer switch frequency at HT aircraft also represents a number digitaldalam digital form.
Figure 6.2 Analog and Digital Measurement Tool
Judging from how to determine the value of the measuring, the measuring instrument / electrical test is divided into two, namely:
– Analog gauges (using the stylus), reading of the measuring values is done by multiplying the appointment of a needle with a constant measuring. For example needle showed 12.5. Being constant measuring is 10 volts. Then the measuring value is 125 volts.
– Digital measuring instrument, pembacan value measuring can be done directly.
Analog Measurement Tools
Analog electrical measuring instrument is a measure of early generations and is still in use. Parts are many electrical and mechanical components that are interconnected. Electrical parts is important, permanent magnet, prisoners meters, and turn the coil. Mechanical parts include needle pointer, scale and nuts regulator pointer.
Figure 6.3 Construction Measurement Analog
Analog measuring devices have rotating components that will react once received electrical signal. How to react to the needle there is a deviating new first shows the number measurements. Or the pointer moves to the designation numbers slowly without any deviation. It used to be a mechanical damper spring that is attached to the needle or blade shaft as anchoring movement of the needle in the form of blades in the air space. At the meter with good industrial grade of iron maupunjenis coil type rotary swivel like a meter mounted on the panel meter is widely used silencer types of spring.
Digital Measurement Tool
Digital measuring devices present widely used with different strengths, inexpensive, easy dioperaikan, and practical. Digital multimeter capable of displaying multiple measurements for miliamper flow, temperature ° C, voltage millivolts, resistance ohm, Hz frequency, power mW until nF capacitance Basically the data / information to be measured is analog. Block diagram of a digital measuring instrument comprises a sensor component, analog signal amplifier, analog to digital converter, a microprocessor, printing equipment, and digital display (Figure 6.4).
Sensors convert electrical and non electrical quantities into a voltage, because the voltage is in the order of mV needs to be amplified by the amplifier input.
Figure 6.4 Principles of Digital Measurement Tool
Analog input signal that has been amplified, of the analog signal is converted into a signal digitaldengan (ADC) analog to digital will be processed by the PC or microprocessor with specific programs and the processing results are stored in digital memory systems. Digital information is displayed in a display or printed with the associated printing press. Digital display will feature a discrete number of 0 to number 9 there are three kinds, namely 7-segment, 14-segment and dot matrix 5 x 7. The digital signal consisting of 0 and 1, when no voltage signal is 0 or OFF, when the first signal voltage or ON.
Figure 6.5 Digital Display