Backup Technical Contact:
Please contact the technical contact for more information, scheduling, and cost estimate, before shipping instruments to the address listed here.
Shipping Address: Shipping Questions and Advice:
CEESI Corporate Loretta Hutchins
54043 County Rd. 37 Tel: 970-897-2711
Nunn, Colorado 80648 firstname.lastname@example.org
|Service ID Number||Description of Services||Fee ($)|
|18800S||Special Tests of Cryogenic Liquid Flow - Calibrations of customer supplied cyrogenic liquid nitrogen from 0.95 kg/s to 9.5 kg/s.||At Cost|
Fees are subject to change without.
NIST’s cryogenic liquid flow calibrations are performed offsite at the Colorado Engineering Experiment Station Incorporated (CEESI) in Nunn, Colorado. These calibrations use a NIST-developed, dynamic weighing system as a primary flow standard to measure totalized mass flow of liquid nitrogen. Mass flow calibrations are performed using liquid nitrogen flows from 0.95 kg/s to 9.5 kg/s, at a pressure in the range 0.4 MPa to 0.76 MPa and at a temperature in range from 80 K to 90 K. Within this flow range, the relative expanded uncertainty is 0.5 % at the 95 % confidence level. Lower flows may be possible; however, the uncertainty at these flows in not yet determined.
If requested, the calibrated mass flow can be converted to volumetric flow using the density of liquid nitrogen from NIST standard reference data. The uncertainty of the density of liquid nitrogen increases the relative expanded uncertainty for volumetric flow to 0.53%.
The calibrations are under NIST’s metrological control, meaning that they conform to NIST/s Quality System. NIST personnel analyze the calibration data, generate the calibration report, and provide a NIST Calibration Certificate. The weighing system and the check standards, as well as all other auxiliary measurements (e.g. temperature, pressure, frequency, voltage) are routinely calibrated by NIST using standards that are traceable to the SI.
References–Flow Measurements at Cryogenic Temperatures
Uncertainty Analysis of the NIST Nitrogen Flow Facility, J. L. Scott and M. A. Lewis, Natl. Inst. Stand. Technol. Tech. Note 1364 (Apr. 1994).
Progress Report on Cryogenic Flow-metering at the National Bureau of Standards, J. A. Brennan, J. F. LaBreque, and C. H. Kneebone, Proc. 1st Biennial Symp. Instrumentation in the Cryogenic Industry, Houston, TX, Oct. 11–14, 1976, 1, 621, Instr. Soc. of America, Pittsburgh, PA (1976).
NBS-CGA Cryogenic Flow Measurement Program, J. A. Brennan, R. W. Stokes, C. H. Kneebone, and D. B. Mann (Proc. ISA Intl. Instrument. Automation Conf. and Exhibit, New York, NY, Oct. 28–31, 1974), Paper in Adv. In Instrument. 29, 612.1 (Instr. Soc. Of America, Pittsburgh, PA, 1974).
Cryogenic Flow Research Facility Provisional Accuracy Statement, J. W. Dean, J. A. Brennan, D. B. Mann, and C. H. Kneebone, Natl. Bur. Stand. (U.S.), Tech. Note 606 (July 1971).