molbloc-L Laminar Flow Element

Key features

Flow ranging from 1 sccm to 100 slm.
Molbloc flow path is the gap between a piston and a close fitting cylindrical bore in the molbloc body.
Different flow ranges are achieved by varying the size of the gap, with larger bodies used for higher flow ranges.

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Product overview: molbloc-L Laminar Flow Element

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Features at a glance

Useable with existing molbox1+ and molbox RFM mass flow terminals and COMPASS software
Integrated filter to protect against contamination
Integral gas temperature conditioning and measurement
Continuous, real-time reading
Can be fully automated
No moving parts

molbloc-L Ranges
molblocs sizes are designated by a number relative to their nominal flow impedance. The nominal impedance results in nominal flow ranges when flowing nitrogen gas with 250 kPa absolute (36 psia) upstream pressure and 50 kPa (7.5 psid) differential pressure across the molbloc. In practice, the molbloc flow range may be quite different from the nominal flow range. The difference comes from differences in density and viscosity between gases and from different molbloc operating pressure calibration options.

Specifications: molbloc-L Laminar Flow Element

Specifications - Standard molbloc-L Calibrations - Used with molbox1+ terminal
Measurement Update Rate	1 second
Range	0 to molbloc full scale depending on gas and molbloc pressure dependent calibration type (see Section 1.2.5.1.3)
Resolution	0.0015 % FS
Linearity	± 0.05 % of reading from 10 to 100 % FS, ± 0.005 % FS under 10 % FS
Repeatability	± 0.05 % of reading from 10 to 100 % FS, ± 0.005 % FS under 10 % FS
Precision¹	± 0.07 % of reading from 10 to 100 % FS, ± 0.007 % FS under 10 % FS
Stability² (1 year)	± 0.09 % of reading from 10 to 100 % FS, ± 0.009 % FS under 10 % FS
Measurement Uncertainty³	± 0.2 % of reading from 10 to 100 % FS, ± 0.02 % FS under 10 % FS
(N2 and any molbox1+ supported gas for which the molbloc in use is calibrated)	1E5 molbloc ± 0.5% of reading from 25 to 100 % FS, ± 0.125 % FS under 25 % FS
¹ Precision: Combined linearity, hysteresis, repeatability. ² Stability: Maximum change in zero and span over specified time period for typical molbox1+ and molbloc used under typical conditions. As stability can only be predicted, stability for a specific molbloc and molbox1+ should be established from experience. ³ Measurement uncertainty (accuracy): Maximum deviation of the molbox1+ flow indication from the true value of the flow through the molbloc including precision, stability and Fluke calibration standard measurement uncertainty.

Specifications - Premium molbloc-L Calibrations - Used with molbox1+ terminal
Measurement Update Rate	1 second
Range	0 to molbloc full scale depending on gas and molbloc pressure dependent calibration type (see Section 1.2.5.1.2)
Resolution	0.0015 % FS
Linearity	± 0.05 % of reading from 10 to 100 % FS, ± 0.005 % FS under 10 % FS
Repeatability	± 0.05 % of reading from 10 to 100 % FS, ± 0.005 % FS under 10 % FS
Precision¹	± 0.07 % of reading from 10 to 100 % FS, ± 0.007 % FS under 10 % FS
Stability² (1 year)	± 0.03 % of reading from 10 to 100 % FS, ± 0.003 % FS under 10 % FS
Measurement Uncertainty³	± 0.125 % of reading from 10 to 100 % FS, ± 0.0125 % FS under 10 % FS
(N2 and any molbox1+ supported gas for which the molbloc in use is calibrated)	1E5 molbloc-L Premium calibration not available
¹ Precision: Combined linearity, hysteresis, repeatability. ² Stability: Maximum change in zero and span over specified time period for typical molbox1+ and molbloc used under typical conditions. As stability can only be predicted, stability for a specific molbloc and molbox1+ should be established from experience. ³ Measurement uncertainty (accuracy): Maximum deviation of the molbox1+ flow indication from the true value of the flow through the molbloc including precision, stability and Fluke calibration standard measurement uncertainty.

Specifications - Standard molbloc-L Calibrations - Used with molbox RFM terminal
	molbloc-L (ranges 1E1-L thru 3E4-L)
Measurement update rate	1 second
Range	0 to molbloc full scale depending on gas and molbloc pressure dependent calibration type (see molbloc-L range sheet tables)
Resolution	0.01 % FS
Linearity	± 0.23 % of reading from 10 % to 100 % FS, ± 0.023 % FS under 10 % FS
Repeatability	± 0.1% of reading from 10 % to 100 % FS, ± 0.01% FS under 10 % FS
Precision¹	± 0.25 % of reading from 10 % to 100 % FS, ± 0.025 % FS under 10 % FS
Predicted stability² (one year)	± 0.15 % of reading from 10 % to 100 % FS, ± 0.015 % FS under 10 % FS
Measurement uncertainty³	± 0.5 % of reading from 10 % to 100 % FS, ± 0.05 % FS under 10 % FS

molbox RFM with Microrange option
	molbloc-L (ranges 1E1-L thru 3E4-L)	molbloc-L (ranges 1E5 only)
Measurement update rate	1 second	1 second
Range	0 to molbloc full scale depending on gas and molbloc pressure dependent calibration type (see molbloc-L tables)	0 to molbloc full scale depending on gas and molbloc pressure dependent calibration type (see molbloc-L tables)
Resolution	0.01 % FS, 0.001 % FS under 0.001 % FS under 10% FS	0.01 % FS
Linearity	± 0.23 % of reading from 1 % to 100 % FS, ± 0.0023 % FS under 1 % FS	± 0.25 % of reading from 5 % to 100 % FS, ± 0.0125 % FS under 5 % FS
Repeatability	± 0.1 % of reading from 1 % to 100 % FS, ± 0.001 % FS under 1 % FS	± 0.2 % of reading from 5 % to 100 % FS, ± 0.01 % FS under 5% FS
Precision¹	± 0.25 % of reading from 1 % to 100 % FS, ± 0.0025 % FS under 1% FS	± 0.32 % of reading from 5 % to 100 % FS, ± 0.016 % FS under 5 % FS
Predicted stability² (one year)	± 0.15 % of reading from 1 % to 100 % FS, ± 0.0015 % FS under 1 % FS	± 0.2 % of reading from 5 % to 100 % FS, ± 0.01 % FS under 5 % FS
Measurement uncertainty³	± 0.5 % of reading from 1 % to 100 % FS, ± 0.005 % FS under 1 % FS	± 0.5 % of reading from 5 % to 100 % FS, ± 0.025 % FS under 5 % FS