ultrasonic level meter
Advantages: non-contact type.
Limitations: dust influence/concave and convex surface influence/noise non-contact;
radar level meter
Advantages: non-contact type.
Limitations: dielectric constant needs/is affected by dust/uneven surface;
Suggestion: Use a four-wire radar with high transmission frequency.
Guided wave radar level gauge
Advantages: measurement of a certain point.
Limitations: dielectric constant is affected by requirements/suspension materials/tension;
laser levels
Advantages: non-contact type
Limitation: dust influence/concave and convex surface influence
Radio frequency admittance level gauge (capacitive level gauge)
Advantages: point contact
Limitations: Need dielectric constant/time drift/temperature drift/suspension material/tension;
Suggestion: It is recommended to adopt imported products.
Heavy hammer level gauge: cable split type and belt type.
Advantages: direct measurement/manual control
Limitation: The traditional cable hammer is prone to broken hammer/buried hammer/rope disorder.
Recommended: with hammer
Ray level gauge
Advantages: non-contact, stable
Limitations: pollution/high price
Weighing level gauge
Advantages: mass/volume can be measured.
Limitations: Earthquake problem/unknown surface condition of materials/high price.
References:
Baidu Encyclopedia: /view/6 12676.htm#6
Material level gauge: /shownews.asp? id=445
PS: Not very professional. It's all information on the internet.