NBSIR 73-290

Development of a Dynamic Pressure

Calibration Technique A Progress

Report

Paul S. Lederer

Electronic Technology Division

Institute for Applied Tectinology

National Bureau of Standards

Washington, D. C. 20234

October 15, 1973

Progress Report Covering period 6-15-73 to 9-15-73

Prepared for NASA Langley Research Center

Hampton, Virginia 23365

NBSIR 73-290

DEVELOPMENT OF A DYNAMIC PRESSURE

CALIBRATION TECHNIQUE A PROGRESS

REPORT

Paul S. Lederer

Electronic Technology Division

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

October 15, 1973

Progress Report Covering period 6-15-73 to 9-15-73

Prepared for NASA Langley Research Center

Hampton, Virginia 23365

U. S. DEPARTMENT OF COMMERCE. Frederick B. Dent. Secretary

NATIONAL BUREAU OF STANDARDS. Richard W. Roberts, Director

Development of a Dynamic Pressure Calibration

Technique

Progress Report for the Period from June 15, 1973 to September 15, 1973

to the

NASA Langley Research Center

NASA Order L-88319

NBS Project 4253456

Prepared by

P. S. Lederer

Project Leader

1 . Introduction

The objective of this task is the conduct of a research and development study to develop a dynamic pressure calibration technique having a flat frequency response to 2000 Hz or greater and amplitude capability

over this frequency range of at least 10 psi peak to peak. This calibration technique is to be capable of directly relating test transducer

characteristics to fundamental units of measurement.

2. Approach

The proposed technique will be based on a hydraulic sinusoidal calibrator previously developed by the NBS Instrumentation Applications Section

and described in NBS Technical Note 720 "A Simple Hydraulic Sinusoidal

Pressure Calibrator" April 1972.

3 . Progress to Date

The electrodynamic vibration excitor used in the original development

is not currently available. It became necessary to procure a new, small

vibration excitor system (from NBS funds, at no cost to NASA) in order to

carry out the work. This system was delivered in August 1973, however the

trunnion base for the shaker is not expected until October.

In the meantime, a universal test fixture was designed, which will

enable the testing of a variety of tube arrangements and transducers with

a minimum of set-up time. Transducers of the flush diaphragm type with

sensing end diameters up to 7/8" (2.22 cm) can be accomodated. In addition to ordinary smooth wall tubes, a variety of tubes with internal

flutes (which increase the wetted inside surface area of the tube) have

been procured from a commercial source. The components for this test

fixture are under construction at this time.

In order to assess the performance of the system with a variety of

liquids, a quantity of a manometer fluid (density 2.95) and of a fluorinebased inert fluid (density 1.88) was procured for use in the modified

hydraulic calibrator. To measure the acceleration applied to the liquidfilled tubes, a piezoelectric accelerometer was purchased. It will be

mounted in the base of the test fixture.

4 . Plans for Next Reporting Period

A variety of tests will be performed on the new pressure calibration

system, involving the use of liquids of different densities and tubes with

a variety of cross sectional configurations. Preliminary tests will be

conducted with a piezoelectric pressure transducer with integral solid

state amplifier. This transducer, purchased for another project, is available for this task. It has adequate sensitivity and a very high natural

frequency.

Subsequent tests will be performed on the pressure transducers which

are to be furnished by the NASA Langley Research Center as indicated in

the work agreement.

FORM NBS-1 14A (1-71

U.S. DEPT. OF COMM. 1. PUBLICATION OR REPORT NO. 2. Gov't Accession

BIBLIOGRAPHIC DATA ^BSIR 73-290

3. Recipient's Accession No.

4. TITLE AND SUBTITLE

Development of a Dynamic Pressure Calibration

Technique A Progress Report

5. Publication Date 9-15-73

6. Performing Organization Code

7. AUTHOR(S)

Paul S. Lederer

8. Performing Organization

NBSIR 73-290

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 4253456

11. Contract/Grant No. NASA Order L-88319

12. Sponsoring Organization Name and Address

NASA Langley Research Center

Hampton, Virginia 23365

13. Type of Report & Period Covered

Progress Report

6-15-73 tn q-15-73

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.) Plans are described for experimental investigation of a hydraulic

sinusoidal pressure calibrator as a basis for development of dynamic

pressure calibration techniques for frequencies up to 2000 Hz.

17. KEY WORDS (Alphabetical order, separated by semicolons)

Dynamic calibration; pressure; transducer.

18. AVAILABILITY STATEMENT

IX] UNLIMITED.

FOR OFFICIAL DISTRIBUTION. DO NOT RELEASE

TO NTIS.

19. SECURITY CLASS

(THIS REPORT)

UNCL ASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF PAGES

5

22. Price

USCOMM-DC 66244.P71