What is N.I.S.T and how does it apply to our sensors?

About NIST (The National Institute of Standards and Technology)

The mission of NIST is to develop and promote measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life. To help meet the measurement and standards needs of U.S. industry and the nation, NIST provides calibrations, standard reference materials, standard reference data, test methods, proficiency evaluation materials, measurement quality assurance programs, and laboratory accreditation services that assist a customer in establishing traceability of results of measurements or values of standards.

NIST traceability is a property of a measurement, not of a device (instrument). For example, you cannot have a flow meter that is traceable to NIST. You can have a calibrated flow meter whose indications are traceable to NIST, providing certain criteria have been met.

NIST traceability requires the establishment of an unbroken chain of comparisons to stated references. Traceability is characterized by the following essential elements:

  • An unbroken chain of comparisons going back to stated references acceptable to the parties, usually a national or international standard;
  • Uncertainty of measurement for each step in the traceability chain. Uncertainty must be calculated or estimated according to agreed methods and must be stated so that an overall uncertainty for the whole chain may be calculated or estimated;
  • Documentation for each step in the chain, performed according to recognized and generally acknowledged procedures;
  • Evidence of technical competence by the laboratories or bodies performing one or more steps in the chain (e.g. by demonstrating that they are accredited);
  • Reference to SI units. The chain of comparisons must, where possible, end at primary standards for realization of the SI units;
  • Calibrations repeated at appropriate intervals. The length in of these intervals will depend on a number of variables, such as uncertainty required, frequency of use, way of use, stability of equipment, etc.

NIST assures the traceability of results of measurements or values of standards that NIST itself provides, either directly or through an official NIST program or collaboration. Other organizations are responsible for establishing the traceability of their own results or values to those of NIST or other stated references.

To learn more, go to www.nist.gov.

In short this means that anyone manufacuring mass airflow sensors, claiming any type of accuracy or repeatibility without certification to back it up, is simply just a claim. For an uncertianty study performed on 9 different HPX sensors at 36 different flow points (324 total data points) click HERE

300-320
350-018
300-101
210-260
300-208
MB2-707
400-201
SY0-401
810-403
200-120
400-101
MB2-707
300-101
210-260
300-208
MB2-707
810-403
200-120
400-101
300-320
350-018
300-101
810-403
200-120
400-101
CISSP
300-320
350-018
300-101
210-260
300-208
MB2-707
400-201
SY0-401
70-462
EX200
100-101
1Z0-803
200-120
210-260
200-310
SY0-401
810-403
300-320
200-120
CISSP
400-101
810-403
300-320
210-060
300-070
210-260
300-075
810-403
300-320
210-060
810-403
300-320
210-060
200-120
CISSP
400-101
810-403
300-320
210-060
300-070
210-260
300-075
300-101
NSE4
EX200
300-115
100-101
ADM-201
N10-006
200-120
CISSP
400-101
810-403
300-320
210-060
300-070
210-260
300-075
200-120
210-260
200-310
SY0-401
810-403
300-320
400-101
70-533
MB2-707
210-060
400-201
350-018
ADM-201
CISSP
1Z0-060
400-051
300-075
400-101
810-403
300-320
210-060
300-070
210-260
300-075
300-101
70-483
70-463
MB2-704
100-101
9L0-012
642-999
300-115
MB5-705
70-461
1V0-601
810-403
200-120
400-101
CISSP
300-320
350-018
300-101
210-260
300-208
MB2-707
400-201
SY0-401
70-462
EX200
300-320
350-018
300-101
210-260
300-208
MB2-707
400-201
SY0-401
70-462
EX200
100-101
1Z0-803
9L0-012
200-310
EX300
ICBB
1Z0-808
AWS-SYSOPS
1Z0-434
300-070
CAS-002
352-001
1V0-601
220-801
N10-006
642-999
200-120
CISSP
400-101
810-403
300-320
210-060
300-070
210-260
300-075
300-101
200-120
400-101
CISSP
210-060
400-201
350-018
ADM-201
CISSP
1Z0-060
400-051
300-075
MB2-704
100-101
9L0-012
642-999