Pros and Cons Analysis of Analog and Digital Multimeters
An analog multimeter is an average‑responding instrument with intuitive and visual readout indication. (The reading value is closely related to the deflection angle of the pointer, hence its high intuitiveness.)
A digital multimeter is an instantaneous‑sampling instrument. It samples once every 0.3 seconds to display measurement results. Sometimes the sampled results are only very similar rather than identical, which makes result reading less convenient compared with analog multimeters.
Analog multimeters generally have no built‑in amplifiers, resulting in low internal resistance. For example, the DC voltage sensitivity of the MF‑10 model is 100 kΩ/V, while that of the MF‑500 model is 20 kΩ/V.
Thanks to the built‑in operational amplifier circuits, digital multimeters can achieve very high internal resistance, often 1 MΩ or higher (which delivers higher sensitivity). Therefore, they exert less influence on the circuit under test and provide higher measurement accuracy.
Due to low internal resistance and shunt‑voltage‑divider circuits built mostly from discrete components, analog multimeters exhibit non‑uniform frequency response (relative to digital multimeters). Nevertheless, analog multimeters feature relatively decent frequency characteristics.
With a simple internal structure, analog multimeters have low cost, fewer functions, easy maintenance and strong overload‑current and over‑voltage resistance. Digital multimeters integrate various circuits such as oscillator, amplifier, frequency divider and protection circuits, thus offering abundant functions. For instance, they can measure temperature, frequency (within a low range), capacitance and inductance, among other capabilities.
Digital multimeters rely heavily on integrated circuits internally and therefore have poor overload resistance. (Though some modern models support auto‑ranging and automatic protection, they are relatively complicated to operate.) They are usually difficult to repair once damaged. Digital multimeters deliver low output voltage (normally no more than 1 V), which creates inconveniences for testing components with special voltage characteristics such as silicon‑controlled rectifiers (SCRs) and light‑emitting diodes (LEDs).
Analog multimeters provide higher output voltage (such as 10.5 V and 12 V) and larger output current. For example, the MF‑500 can produce approximately 100 mA at the ×1 Ω resistance range, making it convenient to test SCRs, LEDs and other components.
