The Strengths of Analog Multimeters and Digital Multimeters
A digital multimeter is an instantaneous sampling instrument. It takes one sample every 0.3 seconds to display the measurement result. Sometimes the sampled readings are only very similar rather than identical, which makes reading results less convenient compared with analog multimeters.
Analog multimeters generally have no built‑in amplifiers and thus feature low internal resistance. For example, the MF‑10 model has a DC voltage sensitivity of 100 kΩ/V, which is regarded as excellent. The MF‑500 model has a DC voltage sensitivity of 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. This minimizes the impact on the circuit under test and enables higher measurement accuracy.
With low internal resistance and shunt and voltage divider circuits mainly composed of discrete components, analog multimeters have non‑uniform frequency response (compared with digital multimeters). Even so, analog multimeters offer relatively good frequency characteristics.
Analog multimeters have a simple internal structure, so they are low‑cost with fewer functions. They are easy to maintain and feature strong resistance against overcurrent and overvoltage.
Digital multimeters integrate various oscillator, amplifier, frequency divider and protection circuits, providing abundant functions. For example, they can measure temperature, frequency (within a low range), capacitance and inductance, and even serve as signal generators.
Since integrated circuits are widely used in their internal structure, digital multimeters have poor overload capability. (However, some modern models support auto‑ranging and automatic protection, yet they are relatively complex to operate and generally hard to repair once damaged.)
Digital multimeters produce low output voltage (typically no more than 1 V), which brings inconvenience 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 instance, the MF‑500 can deliver approximately 100 mA at the ×1 Ω resistance range, making it convenient to test SCRs, LEDs and similar components.
