Lucas Labs: Division of Lucas/Signatone


Address: 393-J Tomkins Ct. Gilroy, CA 95020
(408) 848-2851
Fax: (408) 848-5763

line decor

Lucas Labs Florizel


Testing Systems for Mass Flow Controllers

PDF Download the Florizel Manual  
PDF Download the Florizel Brochure

Florizel- MFC Offline Tester

Florizel uses the Rate of Rise in off line testing of Mass Flow Controllers. Florizel reports linearity, off set, gain of MFC performance. At each flow rate, Florizel will report time to control, mean flow rate, maximum flow, and flow deviation. Analog and Device Net compatible MFCs may be tested.

  Florizel - Testing Systems for MFC
Florizel - Testing Systems for MFC

Dedicated, Fully Automated, Stand Alone


The MFC standard tester is intended to be used with benign test gases (nitrogen, argon etc.) and will yield the actual flow for the gas being tested. An all dry pumping stack is provided for such applications, with or without a front end hybrid turbo/molecular drag pump, according to the base pressure required. This facility eliminates oil from the exhaust of florizel and provides greater latitude for the testing environment. An oil pumped system, at reduced cost, is also available.

"Real" process gases, including corrosive gases, can b e tested provided that an optional corrosive pumping stack is substituted on the MFC Tester, and that the user provides appropriate exhaust system and scrubber facilities where required.

Florizel- MFC Offline Tester

Florizel uses the Rate of Rise in off line testing of Mass Flow Controllers. Florizel reports linearity, off set, gain of MFC performance. At each flow rate, Florizel will report time to control, mean flow rate, maximum flow, and flow deviation. Analog and Device Net compatible MFCs may be tested.

General Description  

Florizel is a dedicated, stand-alone, fully automated testing system for up to 8 mass flow controllers per batch. Tests are carried out under conditions representative of those experienced by the MFC during actual process. The system measures the real time behavior of the MFC. including its start-up transient as well as stability in steady state. The details of the test are user-definable, as are the control bands and limits for each performance parameter. The software compares the actual results with these control bands and automatically give a pass or fail indication without operator intervention.

Click image for larger view



Florizel uses the rate-of-pressure-rise technique to measure the dynamic performance of mass flow controllers under conditions similar to those used in actual processing (i.e. into a vacuum chamber at low pressure). This is in contrast to the standard industry technique, in which MFCs are checked close to atmospheric pressure. As well as the conditions not representing those under which the MFCs will actually be used, there is the further disadvantage that at such high pressures, real gases no longer behave sensibly as ideal gases, necessitating a need for correction factors (not universally applied) and complicating the analysis. A further disadvantage is that the standard technique does not measure the real time behavior of the MFC, so such tests do not quantify short term flow fluctuations or the important switch-on characteristic of the MFC. By contrast, Florizel measures real-time behavior with 25 msec resolution.

The Lucas Technique  

The Lucas technique measures flow rate by monitoring the dynamic pressure behavior as gas flows into the process chamber, which has previously been evacuated and then isolated from the pumping system.

Under these conditions, the pressure increase is due to the ingress of gas into the process chamber. This ingress is in turn due to real and Virtual leaks as well as gas deliberately introduced via the mass flow controller.

  Florizel - MFC Tester
Florizel - MFC Tester
Click image for larger view


The Lucas Florizel separately quantifies the leak rate to that the true flow rate from the MFC can be evaluated. This evaluation relies on a precise knowledge of the test chamber volume as well as the chamber absolute temperature, which is continuously measured by the Florizel.

Florizel looks very similar to the popular Lucas Vacuum Diagnostics System (VDS) except that a sample chamber with multiple connecting ports for the mass flow controllers is mounted on top.

Florizel Automation

All of this testing is carried out fully automatically, after appropriate set-up.

Tests are defined (e.g. test set points, test duration, no. of repetitions, etc.) at the engineer level and stored in the computer's data base for retrieval by the operator during MFC installation. This ensures that the test is carried out objectively and is not subject to operation whims.

Similarly, the pass/fail control bands are defined by the engineer and again saved in a configuration file. Again, the analysis is made objectively by the computer against these standards.

Up to 8 MFCs at a time can be mounted onto the tester (in either horizontal or, optionally, vertical orientations) and tested sequentially in one test cycle,. testing sequentially in one test cycle. Hence, after physical installation of the MFCs and choice of test & analysis configuration, testing is an unattended one-button operation.


All analysis is carried out out rapidly and automatically, without operator intervention, on the testers WindowsTM environment operating system. Data and configuration information is stored in a Microsoft AccessTM database, making it easily available for additional analysis. The measured data of pressure against time during the MFC test are analyzed to yield a quasi-real time flow rate vs. time, corrected for chamber leaks and chamber temperature, etc.

Assessments are made of:

  • Time to reach control
  • Mean flow after control
  • Flow stability - RMS fluctuations of flow
  • Number of short term fluctuations
  • Maximum flow rate
  • Confirmation of supply gas pressure

The actual results are compared with user-defined control bands and alarm bands, which are defined with respect

The control point is defined as that point where the flow rate first appears within the control bands and stays there, except for short-term fluctuations.

Having defined the control point, the mean flow is an indication of the average flow from the control point to the termination of the test.

Similarly the flow stability is a measure of the RMS fluctuations of the flow about that mean flow.

The maximum flow overshoot is measured and checked against yet another user-defined limit.

All points are checked and flagged if, after reaching control, any excursion is outside the user-defined alarm band.

Graphic Display  

  • Orange - The applied set point voltage scaled to sccm
  • Black - The calculated MFC flow using ROR
  • Green - Measured flow feedback from MFC sensor
  • Red - Control band as specified by SEMI E17-91
  • Light Blue - The calculated control time using ROR
  Florizel - Graphic Display
Florizel - Graphic Display
Click image for larger view

This graph shows several measured and calculated data types. The x axis of the graph is time in seconds and the y axis is flow rate in sccm except as noted.

Florizel Specifications

The Lucas Florizel uses the rate of pressure rise technique to test the mass flow controllers. The rate-of-rise technique, more fully described as a measurement technique using the rate of pressure rise in a constant volume to determine flow, is a primary measurement technique and an American Vacuum Society standard. It depends on pressure, volume, temperature and time, all of which can be traced to NIST calibration references. This method is described as AVS standard 2.2- 1968 in Journal of Vacuum Science and Technology 5,219 (1968).

Florizel will meet the following specifications:

  1. Test method: Rate of pressure rise method.
  2. Minimum Pressure of the Test Chamber:
    • <20 mTorr standard.
    • <5*10-5 Torr with optional turbo pumping package
  3. Chamber materials: The main test chamber is fabricated from 304 stainless steel.
  4. Utilities:
    • Electrical: 100-135VAC, Also available 208-240V 50/60 HZ, 10A
    • Pneumatics: 80 - 100psi
    • Test Gas: the system is intended to be used with a clean, dry, chemically inert gas only. This would normally be nitrogen or argon.
  5. External fittings: Standard 1/4" VCR fitting for the MFCs, with "Quick Connect" capability for the test gas. Quick Connectors for both test gas inlet and pneumatics, or per customers choice
  6. Operating temperature: 5-50%C
  7. Computer: PentiumTM based IBM compatible (Dell)
  8. Operating pressure: 5-100 psi for the test gas inlet pressure range from about 1 mTorr up to the full scale of the test chamber manometer(s) (10 Torr standard, 1 & 100 Torr optional).
  9. Flow range: 5sccm to 5 slm, according to manometers chosen
  10. Accuracy: <+/-1% of reading. This is based on the manometers specifications and calibrations, which are traceable to NIST standards.

The MFC tester is built on the same frame as the VDS and is 22" wide x 36" high, and approximately 300 pounds.

<< Back to Lucas Labs Products


          © Lucas/Signatone, All Rights Reserved