
Bios DryCal Primary Gas Flow Calibrators
The Bios DryCal portfolio of products offers the best in flow calibration across a broad spectrum of applications, from the industrial workplace and field locations to the most sophisticated process control systems and analytical laboratories.
All Bios DryCal flow devices are based on our proprietary DryCal® technology. Our innovative dry piston technology eliminates the need for messy, cumbersome bubble provers – and offers the superior accuracy, reliability and ease of operation that has made Bios DryCal products the first choice of flow professionals worldwide.
Learn more about the entire range of Bios DryCal products. Click on the links below to find out more about which meters are appropriate for which applications and visit the Application Notes section of our documents page to see how different flow professionals use Bios DryCal products for a variety of flow needs.

Products by Application
Calibration Services
Manufacturing & Quality Control
Gas Flow Calibrators for Manufacturing & Quality Control
ML-800
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Primary piston provers for the most precise, demanding gas flow applications.
Flow Range: 0.5 – 50,000sccm
Accuracy: +/- 0.15% – 0.25% of reading
ML 1020
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High flow primary piston prover for the most precise, demanding gas flow applications.
Flow Range: 5 – 500 liters per minute
Accuracy: +/- 0.25% of reading
ML One
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Portable primary piston prover for the most precise, demanding, gas flow applications, including corrosive gases.
Flow Range: 5 – 50,000sccm
Accuracy: +/- 0.15% of reading and +/- .01 ccm
Definer 220
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Volumetric and standardized primary flow meter for the environmental compliance and process measurement industries. The Definer 220 allows users to verify gas flow rates, in the field or in the lab, to an accuracy of +/- 1% percent of reading, including temperature and pressure compensation.
Custom Lab Solutions
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Our expertise in flow metrology, coupled with our superior range of flow calibrators and other flow-related products, enables us to develop solutions right for each customer’s individual needs, applications and circumstances.
Occupational Health & Safety
Primary Gas Flow Calibrators for Occupational Health & Safety
Defender
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Field-friendly, rugged and lightweight Defender provides ±1% accuracy calibrations of personal sampling pumps.
Defender 510 – Volumetric Primary Flow Standard
Defender 520 – Enhanced Volumetric Primary Flow Standard with temperature and pressure readings
Defender 530 – Standardized and Volumetric Primary Flow Standard
*Model 520 & 530 include temperature and pressure conditions of the calibration process*
Definer 220
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Volumetric and standardized primary flow meter for the environmental compliance and process measurement industries. The Definer 220 allows users to verify gas flow rates,
in the field or in the lab, to an accuracy of +/- 1% percent of reading, including temperature and pressure compensation.
Environmental Air Monitoring
Gas Flow Calibrators for Environmental Air Monitoring
Definer 220
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Volumetric and standardized primary flow meter for the environmental compliance and process measurement industries. The Definer 220 allows users to verify gas flow rates,
in the field or in the lab, to an accuracy of +/- 1% percent of reading, including temperature and pressure compensation.
Metrology & R&D Laboratories
Gas Flow Calibrators for Metrology & R&D Laboratories
ML-800
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Primary piston provers for the most precise, demanding gas flow applications.
Flow Range: 0.5 – 50,000sccm
Accuracy: +/- 0.15% – 0.25% of reading
ML 1020
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High flow primary piston prover for the most precise, demanding gas flow applications.
Flow Range: 5 – 500 liters per minute
Accuracy: +/- 0.25% of reading
ML One
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Portable primary piston prover for the most precise, demanding, gas flow applications, including corrosive gases.
Flow Range: 5 – 50,000sccm
Accuracy: +/- 0.15% of reading and +/- .01 ccm
Custom Lab Solutions
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Our expertise in flow metrology, coupled with our superior range of flow calibrators and other flow-related products, enables us to develop solutions right for each customer’s individual needs, applications and circumstances.
MFC/MFM Calibration
Gas flow Calibrators for MFC/MFM Calibration
ML-800
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Primary piston provers for the most precise, demanding gas flow applications.
Flow Range: 0.5 – 50,000sccm
Accuracy: +/- 0.15% – 0.25% of reading
ML 1020
![]()
High flow primary piston prover for the most precise, demanding gas flow applications.
Flow Range: 5 – 500 liters per minute
Accuracy: +/- 0.25% of reading
ML One
![]()
Portable primary piston prover for the most precise, demanding, gas flow applications, including corrosive gases.
Flow Range: 5 – 50,000sccm
Accuracy: +/- 0.15% of reading and +/- .01 ccm
Definer 220
![]()
Volumetric and standardized primary flow meter for the environmental compliance and process measurement industries. The Definer 220 allows users to verify gas flow rates, in the field or in the lab, to an accuracy of +/- 1% percent of reading, including temperature and pressure compensation.
Custom Lab Solutions
![]()
Our expertise in flow metrology, coupled with our superior range of flow calibrators and other flow-related products, enables us to develop solutions right for each customer’s individual needs, applications and circumstances.
Software & Accessories
Software & Accessories
Optimizer Software
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With Bios Optimizer™ software, you will do more with your critical calibration data. Optimizer Collect light provides a RS-232 to Microsoft Excel® interface for the Defender 500 series, the Definer 220 and 1020 and the Met Lab Series.
Accessories
We provide a range of accessories designed to enable Bios DryCal products to perform to their full capabilities, and to maintain and protect your Bios DryCal product. Shop for Swagelock® plus, ferrules, leak test caps, filters, cables, tubing, batteries and power adapters, PC cards and other items. Click here to see the complete catalogue and prices for all Bios accessories.


