Which type of flowmeter is relatively maintenance free?

• A. Magnetic flowmeter
• B. Spring probe
• C. Ultrasonic flowmeter
• D. Rotameter

Answer: (B)

Relatively maintenance-free flowmeters are those with few or no moving parts in the fluid path, which minimizes wear, fouling, and drift. Magnetic flowmeters have no moving parts in contact with the fluid; they measure flow via Faraday’s law and electrodes, so maintenance is typically very low. Ultrasonic meters also avoid moving components in the flow path and can be mounted clamp-on, further reducing upkeep. Rotameters rely on a float moving inside a tapered tube, along with wetted parts that can foul or drift, so they generally require more regular cleaning and recalibration. A spring-probe setup offers a simple, sealed sensing element with few wear-heavy parts, which can translate to relatively low maintenance compared with devices with fluid-path movement. The overarching idea is that fewer moving parts and less exposure to the process mean less maintenance overall.