Achieve the lowest uncertainty available for gas flow meter and controller calibrations

The molbox2 flow terminal from Fluke Calibration represents a significant update to the molbloc/molbox gas flow calibration system. molbox2 combined with molbloc flow elements enables you to achieve the lowest uncertainty available for gas flow meter and controller calibrations. A special configuration, molbox2-S, allows you to use molbox-S sonic nozzle flow elements at higher pressures than were previously possible, greatly extending their usable flow range.

A molbloc/molbox2 gas flow calibration system is the ideal solution for calibrating flow meters, thermal mass flow controllers (MFCs), rotameters, turbine meters, bubble meters, and other flow measurement devices. With real-time measurements, no moving parts and supported by traceable calibration in several different gases and operating pressures, molbloc/molbox can handle virtually any calibration application without compromise. molbloc/molbox systems are widely used in many industries, including pharmaceuticals, semiconductors, aerospace, environmental monitoring, energy production, reference gas blending, and research and standards laboratories.

Unparalleled uncertainty specifications

molbox2 innovations enable the molbloc/molbox2 system to achieve the lowest gas flow measurement uncertainties in the industry. The lower uncertainty is made possible by several key improvements, including: 

• Use of Fluke Calibration’s exclusive quartz reference pressure transducer (Q-RPT) technology to precisely measure both absolute and differential pressure. molbox2 Q-RPTs are specially characterized sensors benefitting from the same technology used in Fluke Calibration’s pressure transfer standards.
• “Premium” molbloc calibrations linearize molbloc flow output to better capitalize on existing precision and repeatability.
• Expanded molbloc modelization enables improved performance of molbloc-L laminar flow elements across their range of operating pressures.
• Reduced uncertainty on gas properties utilizing data from NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP10).
• Continued improvements in Fluke Calibration’s molbloc calibration chain, based on fundamental mass- and time-based mass flow measurements using Fluke Calibration’s own dynamic Gravimetric Flow Standard.
• Get accredited and traceable uncertainty specification of 0.5 % of reading for 9 select gases, without calibrations in actual gases, based upon gas properties of NIST REFPROP10 and N2 gas calibration.
• Get traceable uncertainty specifications for 18 additional gases based upon gas properties of NIST REFPROP10 and N2 gas calibration.
• Three time faster flow response speed compared to previous molbox versions.

Four levels of molbloc-L flow element calibration are now available to let you balance uncertainty, accreditation, traceability and costs:

• Premium: ± 0.125 % reading or 0.0125 % full scale of reading flow measurement uncertainty
• Standard: ± 0.2 % reading or 0.02% full scale flow measurement uncertainty
• Accredited and traceable: ± 0.5% of reading or 0.05% full scale flow measurement uncertainty for 9 select gases
• Traceable but not accredited: ± greater of 0.5% reading, 0.05% full scale, or root sum square*[0.2% reading, gas property uncertainties] for 18 additional gases

New molbloc-Ls are eligible for either calibration type. Existing molblocs are compatible with molbox2 at ± 0.2 % of reading uncertainty (standard) and +/- 0.125% of reading uncertainty (premium) with actual gas calibrations. 

molbox2-S expands rangeability—without vacuum pumps

molbox2-S is a special configuration of molbox2 that enables you to cover a wide range (10:1 range turndown) with molbloc-S sonic nozzle flow elements, without requiring costly vacuum pumps. molbox2-S is available with upstream Q-RPT pressure range up to 2 MPa (300 psia) to allow molbloc-S elements to be conveniently used over a wide flow range upstream of flow meters being tested at atmospheric pressure, a common application. This extra rangeability makes it simple to configure a calibration system using fewer molbloc elements and minimal accessories. It also greatly extends the range of your existing molbloc-S elements when a high pressure molbloc calibration is added.

molbloc-S range example with device under testat atmospheric pressure

*Minimum usable flow of molbloc-S elements with SP calibrations are limited by back pressure requirements for sonic flow when used upstream of a device at atmospheric pressure. Flow values are in standard liters per minute referenced to 0 °C.

molbox2-S is designed for use with molbloc-S elements and therefore is configured for absolute pressure measurement only, reducing its cost. It also reduces flow system complexity and overall cost, as well as ongoing recalibration costs.

Use the same molbloc in multiple applications

Multiple molbloc calibrations are now supported for each gas. This means that you can now have a molbloc calibrated separately for use both at high pressure (upstream of the device under test) and low pressure (downstream of the device under test) to support different applications instead of requiring two molblocs or manually loading separate molbloc calibration files. All calibrations are stored on the molbloc EEPROM and the user simply selects the calibration type from the molbox1+ front panel or via molbox2 remote interface.

Fluke Premium Care eligible

When you invest in your Fluke test tools, you want your money to go as far as possible. Fluke Premium Care is a paid offering that provides coverage above and beyond the original product warranty, so you don’t need to worry about unexpected downtime caused by damaged test equipment, accessories, or tools in need of calibration or repair.