Defender 510 & 520
Portable Primary Flow Calibrators for Air Sampling Pumps
The Defender 510 and Defender 520 are portable primary flow calibrators based on Proven DryCal® Technology. Designed for industrial hygiene, air quality and personal sampling pump calibration, they provide reliable volumetric flow measurement across three flow ranges from 5 to 30,000 ccm.
Both models provide ±1% volumetric accuracy and support Single, Continuous and Burst measurements. The Defender 520 additionally measures gas temperature and pressure directly in the flow stream.
For use with non-corrosive, non-condensing gases at less than 70% humidity.
Documentation
Current product documentation from Mesa Labs.
Choose the Right Defender
Defender 510
Volumetric Primary Flow Standard
- Low: 5–500 ccm
- Medium: 50–5,000 ccm
- High: 300–30,000 ccm
- Volumetric accuracy: ±1% of reading
- mL/min, L/min, cc/min and cf/min
- 1/4" ID hose barb
Defender 520
Enhanced Volumetric Primary Flow Standard
- Low: 5–500 ccm
- Medium: 50–5,000 ccm
- High: 300–30,000 ccm
- Volumetric accuracy: ±1% of reading
- Temperature: °C / °F
- Pressure: mmHg / PSI / kPa
- Temperature accuracy: ±0.8°C typical
- Pressure accuracy: ±3.5 mmHg typical
Additional Specifications
- Approximate measurement time: 1–15 seconds
- Single, Continuous and Burst reading modes
- Pressure or suction flow modes
- Operating pressure: atmospheric to 15 PSI absolute
- Backlit graphical LCD
- 6V rechargeable battery, 6–8 hours typical operation
- Dimensions: 140 × 150 × 75 mm
- Weight: 820 g
- Serial RS-232 interface for PC connection
Data & Calibration
Defender flow data can be captured in real time via the RS-232 interface using DryCal Pro software. Mesa Labs recommends annual NIST-traceable calibration to maintain measurement accuracy and traceability.







