Valcom BMS Series

What is it?

The DSBMS01 is a bubbling-type liquid level measurement system. It measures the hydrostatic pressure of a liquid by forcing air through a submerged tube and converting that pressure into an electrical signal that represents the liquid level.

Where is it used?

It is used in industrial environments to monitor the level of liquids inside tanks or vessels. Because the electronics never touch the liquid, it is suitable for harsh, corrosive, dirty, or difficult-process conditions.

How does it work?

A constant flow of air is sent down a tube immersed in the liquid. The deeper the tube tip is submerged, the more pressure is needed for bubbles to escape. The system measures this back-pressure, which is directly proportional to the liquid level, and outputs a standard signal (like 4–20 mA).

What problems does it solve?

It avoids the issues of sensors that must touch the liquid, such as corrosion, fouling, or mechanical wear. It provides a stable, accurate measurement even in demanding environments, and it can monitor multiple tanks using one system, reducing complexity and maintenance.

Electrical/Output

Power supply (2-wire): 12–30 V DC
Power supply (3-wire): 16–26 V DC
Output signal (2-wire): 4–20 mA
Output signal (3-wire): 0–10 V DC or 0–5 V DC
Available pressure ranges: 0–3 mbar up to 0–16 bar
Load (2-wire): R = (Supply Voltage – 12 V) / 0.02 A
Load (3-wire): ≥ 10 kΩ

Measurement Performance

Total accuracy: < ±0.25% FS
Zero offset: < ±1% FS
Overpressure limit: up to 3 × FS
Thermal drift (zero): < ±0.025% FS/°C
Thermal drift (span, piezo): < ±0.02% FS/°C
Thermal drift (span, ceramic): < ±0.01% FS/°C
Long-term stability (piezo): < ±0.15% FS per year
Long-term stability (ceramic): < ±0.12% FS per year
Response time (piezo): approx. 10 ms
Response time (ceramic): approx. 5 ms
Overload capability (piezo): up to ~4 × nominal range
Overload capability (ceramic): up to ~2.5 × nominal range

Environmental and Mechanical

Operating temperature: –40 °C to +85 °C
Storage temperature: –40 °C to +90 °C
Humidity: up to 98% RH (non-condensing)
Ingress protection: IP65
Housing: anodised aluminium
Maximum air supply pressure: < 10 bar

System Components and Configuration

Core module: 27M pressure-to-current converter
Air-flow unit: PR3 regulator with rotameter
Configurations: single-tank or multiposition (up to 15 tanks)
Optional accessories: non-return valve (VNR), air filter/regulator, DIN-rail mounting, custom control panels

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