Technical Seminar on Caliper Checker and Flow Calibration

The Technical Seminar on Caliper Checker and Flow Calibration was organized by The IEEE, Product Safety Engineering Society (PSES) - HK Chapter and Department of Electronic Engineering, City University of Hong Kong on 5 May 2012. Hong Kong Society for Quality (HKSQ) was one of supporting organizations. This talk introduced the high precision length standard calibration and different flow measurement.

In the beginning, Mr. SL Mak (IEEE) gave an welcome speech and introduced guest speakers Ir. Dr. SY Wong (Engineer, Standards and Calibration Laboratory (SCL), ITC) and Ir. TK Chan (Engineer, Standards and Calibration Laboratory (SCL), ITC).

Then Dr George Lau (IEEE & OUHK) gave an opening remark.

The first speaker was Ir. Dr. SY Wong and his topic was "Caliper Checker Calibration". His talk separated into two parts. One was calibration and the other was uncertainty estimation.

Firstly, Dr. Wong introduced the caliper checker and its application to us. It was a kind of step gauge. The upper scale was used for outside caliper and the lower scale was used for inside caliper.

When placed the caliper checker vertically, it could measure height gauge. The setup was shown in the figure.

The close shots of probes on the top and bottom were demonstrated.

The temperature different between unit under test (UUT) and reference standard was very significant on the contribution of uncertainty (because of materials thermal expansion coefficient). The thermocouple attached on caliper checker was shown.

Then light box was used to measure the flatness of caliper checker.

The flatness of bottom was also measured.

Dr. Wong explained the uncertainty model.

Overall results were summarized and discussed.

The second speaker was Ir. TK Chan and his presentation was "Flow Calibration". He introduced six types of flow measurement.
1. Point velocity measurement
2. Mean pipe velocity measurement
3. Volumetric flowrate
4. Total volume measurement
5. Mass flowrate measurement
6. Total mass measurement

Photo of point velocity measurement

Photo of volumetric flowrate

Cup-type anemometer flowrate was upto 24L/min.

Bell prover could be upto 2000L/min.

The 20L standard volume container was showed.

It was 50L standard volume container.

The diagram showed how to test water meter.

The calculation of pressure different between dynamic and static pressure to evaluation the flow rate.

Thermal anemometer was discussed.

The principle of thermal anemometer was to measure the voltage change due to heat loss.

The linear relationship between Uout, Iout and velocity (m/s) was used for calculation.

Another type of anemometer measured the speed of rotation of vane and then calculated the air velocity.

Wind tunnel setup

The closed and open circuit wind tunnels were introduced.

Laser Doppler Anemometer was briefed.

The laser was reflected by particles (about 1um) and then measured the flow rate.

At the end, Ir. Chan briefed the simulation of blockage effect in the wind tunnel.

After the seminar, a group photo was taken for organizers and supporting organizations.

Reference:
The IEEE, Product Safety Engineering Society (PSES) - http://ewh.ieee.org/soc/pses/
Department of Electronic Engineering, CityUHK - http://www.ee.cityu.edu.hk/home/
Hong Kong Society for Quality (HKSQ) - http://www.hksq.org/index.asp