Choosing a level transmitter is rarely about picking the “best” sensor — it is about matching the technology to your medium, tank and signal requirements. This guide walks through the five decisions that actually determine the result, then maps common applications to the right instrument.
On this page
The single most important input is what you are measuring, because it dictates which technologies will even work:
Ultrasonic and radar both work; ultrasonic is usually the lower-cost choice.
Non-contact radar (80 GHz) is far more reliable; ultrasonic struggles with foam and condensing surfaces.
Keep the sensor out of contact and use an Ex ia rated radar for flammable atmospheres.
Radar with a narrow beam reads through dust and uneven surfaces; ultrasonic is defeated by dust and angle-of-repose build-up.
Hydrostatic / pressure transmitters are simple and cheap, but they depend on liquid density.
Non-contact sensors (radar, ultrasonic) sit above the medium and never touch it — ideal for corrosive, sticky or sanitary service. Contact technologies (guided-wave radar, hydrostatic, float) sit in or below the liquid, which can simplify installation in some turbulent or low-dielectric applications but exposes the sensor to the process.
Best all-rounder for difficult media, long range and hazardous areas.
Lowest cost for calm, clean liquids; limited by foam, vapour and long range.
Good for turbulent or low-dielectric liquids and interface measurement, but the probe contacts the medium.
Simplest and cheapest for open, still, conductive tanks; density-dependent.
See the full breakdown in our level measurement technologies comparison.
Once the medium points you at a technology, these numbers lock in the model:
The distance from sensor to empty and to full. Allow for the blind / dead zone at the top.
Confirm the seal and antenna rating; high temperature needs a high-temp option.
±1 mm for custody or dosing; ±5–10 mm is plenty for pump control and alarm.
4–20 mA for PLC/DCS, HART for diagnostics, RS485/Modbus for networks, or 4G wireless for sites with no cable.
Ex ia for hazardous areas; IP rating and antenna material for the environment.
| Application | Recommended | Why |
|---|---|---|
| Water tank, clean well | Ultrasonic | Low cost, calm clean surface |
| Wastewater, foam / turbulence | 80 GHz radar | Reads through foam and agitation |
| Chemical / hazardous tank | Ex ia radar | Non-contact, intrinsically safe |
| Grain / powder silo | 80 GHz radar | Narrow beam through dust |
| Unmanned / off-grid site | 4G solar radar | No power or cabling needed |
| Open still conductive tank | Hydrostatic | Simple, density-based |
For a deeper, industry-by-industry view, start from the applications overview.
Start with ultrasonic or hydrostatic unless range or vapour rules them out.
Choose 80 GHz radar; it is the most forgiving technology.
Use a 4G solar system with cloud alarms.
Send tank drawing and medium; we will spec the model and blind zone for you.
Copyright @ 2026 JiaJia Eye
Scan to add WeChat