With various level detection technologies available, understanding the liquid level sensor working principle is key to optimal selection. Shenzhen StarCore Technology Co., Ltd. explains the mainstream principles and reveals why non-contact capacitive stands out.Comparison of Three Main Principles:1. Float Switch (Mechanical) Principle
Principle: A floating magnet moves a reed switch contact.
Pros: Low cost, simple.
Cons: Prone to jamming; contacts oxidize/arc, short lifespan; requires tank penetration (leak risk); sensitive to orientation.
2. Optical Sensor Principle
Principle: Uses different light refraction in air vs. water. An infrared LED and receiver change state when submerged.
Pros: No moving parts, fast response.
Cons: Probe contacts liquid, prone to fouling/scale; water clarity affects performance; long-term reliability issues.
Principle: As detailed in Article 1, detects capacitance change between sensor and tank wall. Fully isolated from liquid.
Pros:No contact, no wear, extremely long life; immune to scale/contamination; works through non-metal walls, flexible mounting; excellent noise immunity and stability.
Cons: Higher technical barrier in circuit/algorithm design.
Conclusion:In principle, non-contact capacitive sensing offers overwhelming advantages in reliability, lifespan, and adaptability, perfectly aligning with modern dispenser demands for hygiene, safety, longevity, and zero maintenance. This is why Shenzhen StarCore Tech invests heavily in this technology, driving it to become the mainstream standard. Choosing an advanced principle is choosing your product's future.
