Product Overview
Siemens QBM81-10 is a Symaro differential pressure monitor for air and non-aggressive gases in HVAC installations. Its adjustable 100–1000 Pa range supports supervision of filter loading, airflow, fan operation and relative pressure conditions. The device uses a single-pole changeover contact and accepts pressure tubing through 6 mm hose connections. With its covered housing rated IP54, it is intended for practical field mounting in ventilation and building-services equipment. Procurement should verify the complete QBM81-10 suffix, required switching range, pressure connection arrangement, electrical load and installation orientation before the unit is selected for a control or alarm circuit.
Commercial Status
| Product Condition |
Original new |
| Availability |
In stock |
| Official Life Cycle |
PM300: Active Product |
| Warranty |
With 1 year warranty |
Condition, availability and warranty are Stockoems commercial terms and are not manufacturer commitments.
Verified Technical Data
| Manufacturer |
Siemens |
| Complete Part Number |
QBM81-10 |
| Manufacturer Order Code |
BPZ:QBM81-10 |
| Product Type |
Differential pressure monitor / switch |
| Product Family |
Symaro QBM81 |
| Differential Pressure Range |
100–1000 Pa (1–10 mbar) |
| Permitted Medium |
Air and non-aggressive gases |
| Switching Element |
Single-pole changeover contact |
| Pressure Connection |
6 mm hose spout |
| Degree of Protection |
IP54 with cover |
| Ambient Temperature Range |
-30 to +85 °C |
| Maximum Operating Pressure |
50 mbar |
| Net Weight |
0.232 kg |
| Official Country of Origin |
Switzerland |
Product Photo Evidence
Model Identity
Check that the housing label clearly shows QBM81-10 and the Siemens product identity.
Pressure Scale
Confirm the visible adjustment scale corresponds to the 100–1000 Pa range.
Housing and Ports
Inspect the cover, electrical terminals and both pressure connections for completeness.
System Fit and Applications
- Air-filter loading supervision in ventilation equipment
- Fan operation and fan-belt condition monitoring
- Airflow indication in ducts and air-handling units
- Positive or negative relative pressure monitoring in clean rooms and kitchens
Compatibility and Procurement Checks
| Check Point |
What to Verify |
| Range |
Required setpoint lies within 100–1000 Pa. |
| Medium |
Application uses air or a non-aggressive gas. |
| Electrical Circuit |
Contact load and wiring match the control or alarm circuit. |
| Mechanical Fit |
Tubing, connection orientation and mounting position suit the installation. |
Lifecycle Note
Siemens lists QBM81-10 as PM300: Active Product. Use the complete part number and current label data when planning replacement or expansion work.
Frequently Asked Questions
What does QBM81-10 monitor?
It monitors differential pressure, overpressure or underpressure in HVAC air systems.
What is the adjustable range?
The QBM81-10 range is 100–1000 Pa, equivalent to 1–10 mbar.
Can it be used with liquids?
No. The verified medium is air or non-aggressive gas.
Is QBM81-10 discontinued?
No. Siemens identifies this exact product as PM300: Active Product.
What should be checked before ordering?
Confirm the complete model, setpoint range, medium, tubing arrangement, contact load and mounting requirements.
Request Availability and Compatibility Review
Send us the complete part number, required quantity, destination country and product label photos. Our team will check availability, condition, compatibility requirements and shipping options.
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