A computer controlled Dynamic Dilution system for improved accuracy and QA/QC in TO14 standard preparation
Conference
·
OSTI ID:197409
- Entech Lab. Automation, Simi Valley, CA (United States)
Dynamic Dilution is the method of choice for preparing low-level TO14 standards in canisters. One or more cylinders containing NIST certified standards can be blended together with a diluent gas under mass flow control to produce very consistent standards at ppb levels. Blending manifolds can be designed to maintain constant temperatures, pressures, and flow rates during the entire canister filling operation to insure that a proper mass balance is maintained. A Dynamic Dilution system is presented that interfaces to a Windows{trademark}-based operating system allowing implementation of sophisticated flow calculations and feedback control. The dilution system is capable of using temperature compensated vacuum reservoir pressurization to calibrate up to 6 MFC channels unattended. Multiple calibration events can be set up to run sequentially with Means and %RSDs given for the data obtained for improved reliability. Calibrations over a several day period show the stability of mass flow controllers and can indicate the presence of unusually large drifts. These calibration factors are then used by the dilution system to make corrections in flow signals to provide very accurate ppb level standards. The preparation of multiple standards in different canisters without user intervention is also supported for making 2, 5, 10, 20, and 50 ppb level standards for TO14 instrument calibration.
- OSTI ID:
- 197409
- Report Number(s):
- CONF-9405167--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Networking an entire TO14 laboratory into a single Windows-based control system
Preparation and certification of multicomponent VOC compressed gas standards for USEPA Method TO-14
Simplified preparation of TO14 and Title III air toxic standards using a Windows software package and dynamic dilution schemes
Conference
·
Fri Dec 30 23:00:00 EST 1994
·
OSTI ID:197445
Preparation and certification of multicomponent VOC compressed gas standards for USEPA Method TO-14
Conference
·
Mon Dec 30 23:00:00 EST 1996
·
OSTI ID:621347
Simplified preparation of TO14 and Title III air toxic standards using a Windows software package and dynamic dilution schemes
Conference
·
Fri Dec 30 23:00:00 EST 1994
·
OSTI ID:197512