Mesa Labs Defender Primary Flow Meter
Mesa Laboratories

Mesa Labs Defender Primary Flow Meter

Pine Item #51325

Mesa Labs Defender 510 and Defender 520 are the next generation of the DryCal ® DC-Lite and DryCal ® DC-2 flow Calibrators.

Everything you trusted about Mesa Labs DryCal ® technology in the DC-Lite and DC-2 digital flowmeters is available in the Defender 510, 520 & 530 calibrators that make it easier than ever to calibrate air sampling pumps. Measure volumetric flow, standarized flow, which correct for temperature and pressure, or calibrate devices that read in mass flow.

Mesa Labs Defenders are true primary flow meters designed to provide light weight ultra-compact size, incorporating the industry leading DryCal technology. Building on the patented DryCal near-frictionless piston technology, the Defender 500 series incorporates features to make it immune to flow source pulsation without the need for in-line dampers.

Like all Mesa Labs calibrators, the Defender calibrator is easy to use.   Turn it on. Connect it to a sampling pump. Start taking readings. It's as simple as that. Calibrations within a minute with no messy soap bubble solutions to wait on or clean up after.

The Defender 510, 520 and 530 can take hands-free continuous readings while quickly and accurately setting the flow rate on air sampling pumps or other instruments. The Defender calibrators connect to any PC and pre- and post-calibration data can be downloaded with the included Optimizer Collect Light software.


Proven percent of reading accuracy is supported by ISO 17025 accreditation by NVLAP of NIST

Integrated temperature sensors and pressure transducers placed directly in the flow stream for optimum standardized results recording (Bios Defender 520 & 530)

Housed in a molded case with rubber handgrips for a better feel and a sleeker more contemporary look

Large illuminated flow cell viewing window

Navigation menu and a large illuminated graphical display with zoom feature

Rated for extreme cold operation down to -20 ºC

RoHS (Restriction of Hazardous Substances) compliant for Europe

Automatic Shutoff

Choose between flow units – mL L cc or cf

Include up to one hundred readings in a group average

Take individual readings continuous hands-free readings or set to read in time intervals anywhere from one minute to sixty minutes between readings

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Technical Specifications

Flow Range: DryCal Defender Medium (M) Flow:50 - 5000 mL/min
Pressure (Defender 520 only) mmHg PSI kPa
Gas CompatibilityUse with non-corrosive non-condensing non-combustible gases less than 70% humidity
Accuracy: Volumetric (Defender 510 or 520)±1.0%
Volumetric FlowmL/min L/min cc/min cf/min
Flow Range: DryCal Defender Low (L) Flow:5 to 500 mL/min
Flow Range: DryCal Defender High (H) Flow:300 - 30000 ml/min
Flow ModesSuction or Pressure
Temperature & Pressure SensorsIn the flow stream\nPress: 3.5 mmHg (typical) 7.0 mm (max)\nTemp: 0.8 °C (typical) 1.3 °C (max)
Reading StylesSingle (manual) Continuous or Burst with averaging function user-selectable from 1 to 100 measurements
Battery System6V rechargeable sealed lead-acid 6-8 hours typical operation
Battery Operational Time (5 cycles/min) 3 hours backlight on 8 hours backlight off
Pressure & Suction Fittings¼” ID Hose Barb
Operating Pressure (Absolute) 15 PSI
Laboratory AccreditationBacked by ISO 17025 accreditation by NVLAP of NIST
Instrument CertificationRoHS and CE Compliant