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Measurement performance with heavy foam and floating debris
Time:2026-08-07 Browse: 129
Answer: Foam thicker than 3‑4 cm triggers an “insufficient echo energy” alert. As foam thickness increases, radar signal penetration degrades, the sensor fails to capture valid target echoes, and outputs weak echo fault signals.
At a glance: foam and floating debris sit between the antenna and the true surface. Because foam is mostly air, it reflects very little signal — thick foam triggers the alarm and can make the reading drop out entirely.
How foam affects the reading
Foam up to 3–4 cm: usually tolerated; the radar still reads through it.
Thicker than 3–4 cm: triggers the Insufficient Echo Energy alarm as penetration degrades.
Very thick or wet foam: the sensor can no longer capture a valid echo and the reading freezes or drops out.
Step-by-step diagnosis
Measure foam thickness. Is it transient (mixing, aeration) or permanent? Transient foam may need only a delay or filtering setting.
Check floating debris. Floating solids create sporadic false echoes — visible as jitter in the echo spectrum.
Read the echo spectrum. A stable true peak buried under noise means weak return; enabling nearest-peak detection or raising RF power often recovers it.
How to fix it
1. Raise the installation height
Mount the antenna above the foam layer so the beam only crosses air before hitting liquid. This is the most reliable fix.
2. Tune the signal
Increase RF transmit power and enable spurious-echo learning to reject debris reflections. Widen the sliding-window filter (e.g. 10/30/60) to smooth spikes — at the cost of slower response.
3. Change technology for severe foam
When foam is persistently thick, a guided-wave radar (TDR) or a hydrostatic / pressure transmitter reads through foam reliably. For light, transient foam, an 80 GHz FMCW unit with high power is usually sufficient.
Recommended sensor for foam applications
Not sure which technology fits your tank? Compare options in the Jiajia Eye radar level transmitter line-up, or send us your process data (liquid, foam type, tank height) and we will recommend a sensor — radar, guided-wave, or pressure — that reads accurately under your exact conditions.
