510, 520, 530+

  • High accuracy. Calibrators in Mesa’s DefenderTM Series are backed by Proven DryCal® technology and have a reading uncertainty of less than 1%. 
  • Durability. All DryCal calibrators are field-proven and have provided IH professionals with reliable performance for decades. 
  • Real-time flow data. Calibrator flow data is captured in real-time with our DryCal Pro software, directly uploaded to a PC, and exported to a Microsoft environment. 
  • Convenient mail-in factory calibration. An annual NIST-traceable calibration by Mesa’s ISO-accredited facility provides a defensible audit trail and full refurbishment. 
  • Trusted accreditation. Mesa Labs is a fully accredited ISO-17025 facility with a 0.08% Scope of Accreditation for gas flow by NVLAP of NIST. "NVLAP Lab Code 200661-0"
Technical Specifications
Product Options
Document Downloads

Technical Specifications

Defender Series

  • Approximate Time per Reading: 1-15 seconds
  • Reading Styles (with averaging function userselectable from 1 to 100 measurement): Single (manual), Continuous or Burst
  • Gas Compatibility: Non-corrosive, non-condensing, less than 70% humidity
  • Flow Modes: Pressure or Suction
  • Measurement Cell Style: Integrated
  • AC Adapter/Charger: 12V DC, >250ma, 2.5 mm center positive
  • Battery System: 6V rechargeable, sealed lead-acid, 6-8 hrs typical operation
  • Battery Operational Time (5 cycles/min): 3 hrs backlight on, 8 hrs backlight off
  • Pressure and Suction Fittings: 1/4” ID Swagelok® compression fittings, 3/8” fittings on High Model
  • Warranty: 1 year; battery 6 months
  • Storage Temperature: 0-70°C
  • Ambient Humidity: 0-70%, non-condensing
  • Operating Pressure (Absolute): Atmospheric, 15 PSI Max
  • Display: Backlit graphical LCD
  • Data Port (for PC interface): Serial (RS-232)
  • Data Cable (for PC interface): 1 meter (Defender Data Port to PC included)
  • Protective Case: Pelican case available
  • Dimensions (H x W x D): 5.5” x 6” x 3” / 140 x 150 x 75 mm
  • Weight: 29 oz / 820 g
Model             Defender 510 Defender 520 Defender 530+
 Flow Ranges

Low: 5-500 ccm

Medium: 50-5,000 ccm

High: 300-30,000 ccm

Low: 5-500 ccm

Medium: 50-5,000 ccm

High: 300-30,000 ccm

Low: 5-500 ccm

Medium: 50-5,000 ccm

High: 300-30,000 ccm

Volumetric Accuracy 1% 1% 0.75%
Standardized Accuracy N/A N/A 1%

User Selectable Volumetric Units

mL/min, L/min, cc/min, cf/min

mL/min, L/min, cc/min, cf/min mL/min, L/min, cc/min, cf/min
User Selectable Standardized Units N/A N/A smL/min, sL/min, scc/min, scf/ min
User Selectable Temperature Units N/A °C, °F °C, °F
User Selectable Pressure Units N/A mmHg, PSI, kPa mmHg, PSI, kPa
Pressure Accuracy N/A ± 3.5 mmHg (typical) ±7.0 mm (max) ± 3.5 mmHg (typical) ±7.0 mm (max)
Temperature Accuracy N/A ± 0.8 °C (typical) ± 1.3 °C (max) ± 0.8 °C (typical) ± 1.3 °C (max)
Industry Applications Industrial Hygiene, Air Quality Industrial Hygiene, Air Quality Manufacturing, Air Quality, Personal Gas Sampling
Pressure and Suction Fittings 1/4" ID Hose Barb 1/4" ID Hose Barb  1/4" ID Swagelok ® compression fittings, 3/8" fittings on High Model

Product Options

All Defender series products offer single, continuous, and burst reading options. The series is highlighted as a calibration method in the OSHA Technical Manual. 

By connecting your computer to the Defenders RS-232 port, you’ll get real-time flow and data capture using DryCal Pro Software. Check out our product line: 


Defender 510 • Volumetric Primary Flow Standard 

The Defender 510 is the base model of the Defender series. This model is primarily used for 

  • Personal Sampling Pump Calibration 
  • Volumetric Flow Calibration 


Defender 520 • Enhanced Volumetric Primary Flow Standard 

  The Defender 520 is the intermediate model of the Defender Series. This model provides: 

  • Flow Calibration where you want to know Temperature/Pressure 
  • A more affordable option 


Defender 530+ • Standardized Primary Flow Standard 

  The Defender 530+ is the most enhanced model of the Defender Series. This model provides: 

  • Standardized (Mass Flow) Readings 
  • Ambient Air and Industrial Flow Standard Applications 
  • Options to use Standardized or Volumetric Flow Applications

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