CALIBRATION OF SPECTRAL IRRADIANCE SOURCES USING A FIBER-COUPLED SYSTEM

The standards and Calibration Laboratory has recently developed the calibration service for the enclosed-type irradiance light source in the spectral range from 300 nm to 850 nm. The calibration is based on the source-based method measured by a fiber-coupled system. In this paper, the calibration setup, measurement model and the associated uncertainty are presented. The expanded measurement uncertainty is estimated to be less than 3,3 % over the measured spectral range which can support the needs from the testing and certification industry.

Interaction between the Standard and the Measurement Instrument during the Flow Velocity Sensor Calibration Process

The complex ventilation system development process is associated with the stages of modelling, design, execution, and testing. Each of these steps requires the use of measuring equipment that is capable of determining the basic parameters of the flow. In the process of calibrating instruments for measuring flow velocity, one of the limitations is the size of the calibrated devices positioned in the test section of the wind tunnel. This is related to the change in the flow condition within the vicinity of the calibrated anemometers, which is caused by the blockage effect. Instruments with significant dimensions in relation to the cross-sectional area of the wind tunnel test section may have an impact on the reference velocity as indicated by the standard. In such cases, the calibration results may be affected by additional systematic error. This article presents a study of this effect using a real case of a calibration laboratory and commonly used sensors. The influence of different types of air velocity sensors on velocity profiles in the measurement standard area is also investigated. Additionally, the area of the blockage effect is described. The obtained results indicate the possibility of a proper placement for the measuring standard due to minimization of the flow-blocking effect.

Pressure Calibration of Quarter-inch Working Standard Microphones by Comparison

The Standards and Calibration Laboratory (SCL) in Hong Kong has developed a system for calibration of quarter-inch working standard (WS3) microphones which automates the measurement process and generates digital calibration certificates (DCC) to meet the growing demand for microphone calibration services in Hong Kong. This paper describes (i) the method of determining the pressure sensitivity of a microphone combination unit from 20 Hz to 20 kHz by the comparison technique in accordance with the International Standard IEC 61094-5, (ii) the measurement model and uncertainty evaluation, and (iii) the automatic system which facilitates the calibration process and generation of a digital calibration certificate.

Decision Rules: How one Calibration Software Vendor Approaches the Various Options of “taking uncertainty into account”

The latest release of ISO/IEC-17025 requires that calibrations laboratories must take their measurement uncertainty into account when making a statement of conformity to a specified requirement. The standard further requires the laboratory to take the risks (both consumer and producer risk) into consideration when employing these “decision rules”. While 17025 does not specify exactly what your laboratory decision rules must be, there are numerous documents that can offer guidance on the subject. Each method has its pros and cons relating to complexity, statistical rigor, and tradeoffs between the two sides of the risk equation. The modern calibration laboratory struggles to offer affordable services to customers who demand increased accuracy in their equipment. The old 4:1 TAR rule of thumb is long gone and with the customer shop floor equipment reaching the accuracies of the laboratory standards of just a few years ago, the challenge of maintaining an appropriate ratio of uncertainty is becoming progressively more difficult. This paper looks at the most common methods of taking that measurement uncertainty into account and how our software is configured and structured to allow the laboratory to apply several different methods depending on their individual customer requirements. These approaches are not fixed, one size fits all, but are customizable by the laboratory, to fit their customers exact requirements, even if their customers have widely different demands.

Calibration of Timing Parameters of Still Image Cameras and Video Cameras by a Two Dimensional LED Array

This paper presents a t wo-dimensional 10 x 10 LED array system developed in-house at t he Standards and Calibration Laboratory (SCL) for the calibration of timing parameters of still image cameras and video cameras. In this paper, the circuit design and the calibration methods for cameras of different shutter types (rolling shutter or global shutter) are presented. This LED array may also be used to verify the shutter type of cameras. The frequency of the clock signal applied in the calibration is traceable to the SI through the cesium beam frequency standard maintained at SCL.

Accurate Clinical Tympanic Thermometer Measurement System at NMISA

Infrared ear thermometers allow users to measure body temperature quickly and non-invasively by inserting a probe into the patient’s ear canal. The effectiveness of tympanic ear thermometers is dependent on how accurate their measurement is. This prompts the demand for accurate and reliable calibration of ear thermometers. Developing capability and providing traceability to the health care facilities in South Africa have become crucial, as there is no calibration laboratory that provides such a service. A standard ear-thermometer black-body source system that is traceable to ITS-90 temperature has been constructed and assembled at the NMISA temperature laboratory. The ITS-90-traceable measurement system developed has a measuring capability of 40 mK (k=2) to 70 mK (k=2) in the temperature range of 35.5 °C to 41.5 °C. At the human body temperature of 37 °C an uncertainty of 45 mK (k=2) is achieved.

Ketepatan pemorsian hidangan di RSUD Dr. Tjitrowardojo Purworejo

Maintaining food quality can be done by supervising portion standards. One of the important components in food management is the quality of human resources. The research objective was to determine the accuracy of serving dishes in terms of the characteristics of the serving staff. This observational study had a cross-sectional design. Collecting data in July 2019 at the Nutrition Installation of Dr. Tjitrowardojo Purworejo hospital. The research subjects were 14 people who were taken by a purposive sampling method. Subject characteristics consist of age, gender, level of education, and length of work. The accuracy of serving dishes was categorized into precise (±10% of standard serving) and imprecise (<10% or >10% of standard serving). The weighing method is used to determine the portion produced by the research subject. The research instrument is a digital food scale that has been calibrated at the BBKKP Calibration Laboratory with the number: 310/Labkal/V/2019. Data analysis used the Spearman Rank Correlation test. The results showed that most of the dishes were not done correctly (85,7%). Statistically, the characteristics of the serving staff do not show a correlation with the accuracy of serving dishes (p > 0,05). Concluded, there is no correlation between the characteristics of the proponents with the accuracy of the serving dishes in Dr. Tjitrowardojo Purworejo hospital.