Ensuring reliable level measurement in tanks with internal obstructions
What happened
Process Online explains that non-contacting radar level transmitters can misinterpret echoes from internal tank structures, producing false level readings. The article points out that misreads can lead to overfill, underfill or downstream equipment damage and that mitigation often requires repositioning, different sensors or additional commissioning. Watch whether buyers start treating obstructed-tank measurement as a recurring contract requirement
Buyer takeaway
Treat obstructed-tank level measurement as an operational risk that must be validated and priced in supplier bids
Cost / money
Repositioning or sensor retrofits are execution costs that should be scoped into proposals where the problem is recurring
Supplier / commercial
Vendors offering on-site commissioning and sensor-selection expertise will be preferred in negotiations for these scopes
Safety / operations
Acceptance tests must include echo-validation under real conditions to prevent overfill or dry-run pump events
What to watch
Article gives technical guidance but limited retrofit cost detail; verify vendor claims on mitigation effectiveness before accepting 'no-change' recommendations
Key facts
- Non-contacting FMCW radar is a preferred option but struggles with obstructions
- False echoes can cause overfill, underfill and downstream equipment issues
- Mitigations include repositioning transmitters or using alternative sensor technologies
Source excerpts
Figure 2: Internal equipment can make it challenging for a non-contacting radar level transmitter to differentiate the true surface echo from false echoes coming from obstructions. Strategies for mitigating false echoes While tanks containing internal structures present clear challenges for non-contacting radar level transmitters, a number of strategies can help to reduce or eliminate the impact of false echoes
Such interventions represent significant operational disruption and cost, and are rarely justified unless a proven and recurring problem exists. Operational conditions also affect performance
Signals corresponding to known obstructions are identified and effectively ignored, while changes in the echo profile indicate movement of the actual product surface. This enables accurate, continuous level measurement, even in tanks with complex internal geometries
