Ultrasonic Flow Meter (Clamp-On / Inline) — NPK Industries
Ultrasonic Flow Meters have become one of the most preferred choices for industries looking for non-intrusive, reliable, and maintenance-free flow measurement. At NPK Industries, we supply advanced ultrasonic technologies from Fuji Electric (FSSC / FLV series) and Krohne Marshall (Optisonic 6300)—suitable for everything from process water, chilled water, chemical streams, dairy utilities, HVAC, ETP/STP, oil & gas audits, and large pipeline measurement.
Working Principle — Explained Clearly
Ultrasonic meters operate using Transit-Time Differential Technology (most common):
➤ Transit Time Method
Two ultrasonic sensors transmit sound waves:
- One in the direction of flow
- One against the direction of flow
When flow increases, the downstream signal travels faster and upstream signal travels slower.
The meter calculates the time difference:
ΔT = Time downstream – Time upstream
Flow ∝ ΔT
This provides velocity, which is converted into volumetric flow using pipe dimensions.
Clamp-On vs Inline — Which One Should You Choose?
Feature | Clamp-On Ultrasonic (FSSC / Optisonic 6300) | Inline Ultrasonic |
Installation | Outside pipe (non-intrusive) | Requires pipe cutting |
Accuracy | ±0.5–2% | ±0.2–0.5% |
Maintenance | Zero touching fluid | Low |
Fluid type | Clean water, utilities | Clean & process liquids |
Cost | Lower | Higher |
Portable version | Available | Not available |
Ideal For | Audits, chilled water, large pipes | Process-critical measurement |
Key Advantages for Clients
✔ Non-Intrusive — No Cutting, No Downtime
Installation takes minutes. Ideal for operational plants.
✔ Works on all pipe materials
Metal, PVC, HDPE, MS, SS, asbestos, and even concrete.
✔ Zero pressure drop
Since nothing is inserted into the pipe.
✔ Cost-effective for large pipelines
No expensive flanges or heavy-duty installation.
✔ Portable versions available
For audits, energy studies, and verification.
✔ Energy Metering (BTU Monitoring)
With built-in temperature inputs.