• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.99-102
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• 2007

Pressure Sensitive Paint(PSP)는 압력에 반응하는 도료를 뜻한다. PSP를 이용하여 압력을 측정 하기 위해서는 paint calibration과 PSP를 도포한 모델의 풍동실험이 필요하다. PSP는 이 두 가지의 결과를 이용한 이미지의 후처리과정을 통하여 압력정보를 포함한 이미지를 얻을 수 있는 신기술이다. 본 연구에서는 PSP에 필요한 장치 및 설비들을 구성하고 PSP를 이용하여 calibration 실험을 실시하였다. 본 연구를 통해 얻어진 calibration chamber의 설계 및 제작 방법으로 진보된 calibration 시스템을 연구할 수 있는 능력을 배양하였다.

• 대한의생명과학회지
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• 제22권4호
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• pp.115-126
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• 2016

Audiometric calibration is a prerequisite for securing the reliability of audiometric test results by checking the internal consistency of the relevant instrument. The purpose of this review is to help instrument operators understand the calibration procedure of aural acoustic immittance instrument which is frequently used for objective assessment. By referring to the latest international standards and the national standards relevant to the aural acoustic immittance instrument, the following parameters will be reviewed: 1) introduction of performance characteristics, 2) detailed procedure of the calibration method. According to the newest international and national standards [IEC 60645-5 (2004), ANSI S3.39-1987 (R2012)], the aural acoustic immittance instrument basically includes six components: 1) calibration cavity, 2) acoustic immittance analysis system, 3) probe assembly/unit and signal, 4) pneumatic air-pressure pump system, 5) acoustic reflex activator system and 6) tympanogram and acoustic reflex plotting system, each of these components should meet set standards. The result of behavioral hearing tests is influenced by various complex factors including the examinee's cooperation, background noise of the examination room, measurement method, skill level of the audiologist and calibration status, but the objective hearing tests is more influenced by the calibration status of the instrument than any other factors. The audiologist should take full responsibility for the reliability of the hearing test result, so he/she should carry out the calibration check and adjustments of aural acoustic immittance instrument periodically and maintain the instrument continuously by referring to the newest standards and the manufacturer's instruction manual.

• 소성∙가공
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• 제18권8호
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• pp.640-645
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• 2009

Recently, boss and rib test based on backward extrusion process was proposed to quantitatively evaluate the interfacial friction condition in bulk forming process. In this test, the tube-shaped punch with hole pressurizes the workpiece so that the boss and rib are formed along the hole and outer surface of the punch. It was experimentally and numerically revealed that the height of boss is higher than that of the rib under the severe friction condition. This work is focused on the effect of the punch design and flow stress on deformation pattern in boss and rib test. From the boss and rib test simulations, it was found that there is slight variation in both the heights of boss and rib according to the length of punch land, nose radius, and face angle. However the hole diameter of the punch and the clearance between the punch and die have a significant influence on the calibration curves showing the heights of the boss and rib. In addition, the effect of flow stress on the calibration curves was investigated through FE simulations. It was found that there is no effect of strength coefficient of the workpiece on the calibration curves for estimation of friction condition. On the other hand, the strain-hardening exponent of the workpiece has a significant influence on the calibration curve.

• 센서학회지
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• 제32권6호
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• pp.447-454
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• 2023

The Korea Laboratory Accreditation Scheme (KOLAS) operates accreditation programs for ensuring measurement traceability with the International System (SI) of Units - the highest calibration standard that measurements can be tested against. As of September 2023, there are 70 KOLAS-accredited laboratories in the Republic of Korea that specialize in humidity calibration. Among them, 32 KOLAS laboratories, along with one laboratory not affiliated with KOLAS, participated in the proficiency test (PM 2023-11) for relative humidity transducers in 2023. This proficiency test was conducted within a relative humidity range of 20-90% at a temperature of approximately 20 ℃, taking into consideration the calibration and measurement capability (CMC) of the participating laboratories. The primary objective of the proficiency test was to establish the measurement equivalence between each participating laboratory and the reference laboratory, by calculating the number of equivalence (En). When |En| was less than 1, the measurements from the participating and reference laboratory were equivalent. Out of the 33 participating laboratories, 32 successfully met this criterion and passed the proficiency test.

• 한국도로학회논문집
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• 제8권3호
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• pp.155-162
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• 2006

시험도로 줄눈 콘크리트포장에 대하여 48시간 동안 시간에 따른 처짐의 변화를 측정하였고 이를 이용하여 컬링거동의 보정방안을 도출하였다. 임의 시간 슬래브의 중앙 처짐/줄눈 처짐이 임의 시간 중앙 처짐/기준 시간 중앙 처짐 사이의 관계를 회귀분석을 통해서 얻어내었다. 임의시간에 측정된 처짐으로부터 하루 가운데 최소 처짐이 나타나는 기준시간 처짐으로의 변환은 회귀곡선을 통해 추정 하였고 데이터 축적을 통해 컬링거동 보정 방안의 하나로 제시 할 수 있을 것으로 판단되었다.

• 한국전자파학회논문지
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• 제18권2호
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• pp.166-176
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• 2007

측정 분야나 교정 분야에서 측정 불확도를 보고하는 것은 매우 중요하다. 정보통신부 전파연구소에서는 EMI 측정 시험소를 위하여 안테나 교정 서비스를 제공하고 있는데, 안테나 교정의 정확성은 측정 불확도 평가로 집약되어, EMI 시험의 신뢰성을 판가름하는 시금석이 된다. EMI에 관한 국제기구인 CISPR에서는 2005년 말에 안테나 교정에 대한 최초의 표준 초안인 CISPR/A/644/C를 내놓았다. 이 초안은 안테나교정 및 관련된 측정 불확도를 포함하고 있다. 본 논문에서는 이 문서를 근간으로 전파연구소 이천의 안테나 교정시험장에서 EMI용 다이폴안테나를 교정할 때의 측정 불확도를 산출하였다. 전파연구소의 안테나 교정 방법은 자유 공간 안테나 인자를 측정하는 3-안테나의 height scanning averaging 법으로서, 본 방법에 의하여 안테나가 교정될 때 측정 결과에 영향을 미칠 수 있는 모든 불확도 요인을 고려하였다.

• 한국지반신소재학회논문집
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• 제14권1호
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• pp.59-65
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• 2015

TDR을 이용한 흙의 건조밀도와 함수비의 새로운 보정 방정식을 검증하기 위해 본 연구를 수행하였다. 기존의 보정 방정식이 제안되고 몇몇 연구자들에 의해 새로운 보정 방정식을 개발하는 연구가 진행되고 있다. 기존의 보정 방정식이 함수비가 높은 세립토와 느슨한 토질에서는 적용되기 어려워 새로운 보정 방정식을 개발하였다. 이에 따라 본 연구에서는 새로운 보정 방정식을 소개하고 기존의 실험과 비교해 새로운 보정방정식의 국내지반과의 적용성을 검토를 수행하였다. 그 결과 함수비의 보정방정식에 오차가 발생하여 함수비의 새로운 보정방정식을 개발하였고, 개발한 보정방정식을 검토한 결과 95%이상의 정확도를 보여준다.

• 센서학회지
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• 제14권4호
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• pp.231-236
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• 2005

Calibration capability was evaluated using the reference-grade platinum resistance thermometer (PRT) in the temperature range of $-50^{\circ}C$ to $250^{\circ}C$ for the national calibration centers. The reference-grade PRT was calibrated at the several fixed points, which was composed by the freezing points of Sn, In, the melting point of Ga and the triple point of water and Hg, before and after the round-robin test (RRT) experiments. The temperature scale of reference-grade PRT was compared to the local standard PRT's using the system of the national calibration centers. $E_{n}$ values was calculated by the temperature difference between the reference-grade PRT and the local standard PRT, and the best measurement capability. Finally, the capability of the national calibration centers was evaluated by the $E_{n}$ values.

• 공업화학
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• 제31권3호
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• pp.334-337
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• 2020

한국인정기구(KOLAS)는 시험 및 교정기관이 KS Q ISO/IEC 17025 요구사항에 맞추어 적절하게 운영하고 유효한 결과를 생산할 수 있도록 표준안을 제시하고 있다. 국가표준기본법(시험·검사: 시험·검사기관 인정, 교정: 국가교정제도의 확립)을 근거로 운영하고 있다. 최근, 국제시험소인정기구(ILAC)가 자격기준을 강화함에 따라 공인시험·교정기관들도 요구사항(KS Q ISO/IEC 17025:2017)에 맞추어 2020년 11월까지 전환을 완료해야 한다. 국내에서 운영되고 있는 899개 KOLAS 인정시험·검사와 교정기관이 여기에 해당된다. 여기에서는 적격성에 대한 주요 일반 요구사항을 요약하였다.

• 핵의학기술
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• 제20권2호
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• pp.75-79
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• 2016

Purpose The ASAN Medical Center, Nuclear Medicine performs TSH (Thyroid stimulating hormone) and FT4 (Free Thyroxine) tests 8 times per day. Accordingly, 70 ~ 80 kit tubes are consumed every day for the measurements and the time consumed for reagent dispensing averages over 170 seconds, where the TAT (turnaround time) may be effected when the number of test samples is larger than expected. Therefore, the following test was conducted with the purpose to reduce the number of kit tubes consumed, and reduce the time for reagent dispensing. Materials and Methods The test is based on applying the same reagent for tests where the number of samples is 30 or less. The test for TSH was conducted 9 times from July $1^{st}$ 2015 to July $10^{th}$ 2015. The test for FT4 was conducted 4 times from June $18^{th}$ 2015 to June $22^{nd}$, 2015. Standard Solution No.2 (0.153 uU/mL) and No.5 (4.96 uU/mL) was selected as the two-point standards for the TSH test, and Standard Solution No.3 (0.777 ng/dL) and No.4 (2.044 ng/dL) was selected as the two-point standards for the FT4 test. 38 test samples were subject to correlation analysis. Results For TSH, the result of the normal test shows ranges of 0.20 ~ 0.37 uU/mL for Control1, 0.53 ~ 0.71 uU/mL for Control2, and 6.77 ~ 7.94uU/mL for Control3, while the result of two-point calibration curve test shows ranges of 0.18 ~ 0.27 uU/mL for Control1, 0.53 ~ 0.71 uU/mL for Control2, and 7.30 ~ 8.52 uU/mL for Control3. For FT4, the result of the normal test shows ranges of 0.85 ~ 0.94 ng/dL for Control1 and 4.23 ~ 4.57 ng/dL for Control2, while the result of two-point calibration curve test shows ranges of 0.61 ~ 0.75 ng/dL for Control1 and 3.88 ~ 5.71 ng/dL for Control2. For TSH, the CV% of the normal test for Control1, Control2 and Control3 are 10.5, 3.3 and 3.6 respectively, while the CV% of the two-point calibration curve test for Control1 and Control1 are 12.4, 8.2 and 5.1 respectively. The result shows an outstanding correlation of TSH: y = 0.9985x - 0.0459 $R^2=0.9986$. For FT4, the CV% of the normal test for Control1 and Control2 are 0.70 and 0.71 respectively, while the CV% of the two-point calibration curve test for Control1 and Control1 are 8.7 and 16.2 respectively. The result shows an outstanding correlation of FT4: y = 1.2674x - 0.1133 $R^2=0.9824$. Conclusion The two-point calibration curve can be efficiently applied for TSH in cases where the number of test samples is not large, since the number of samples to be re-tested increases when the result is abnormal from the calibration curve. The two-point calibration curve test should not be applied for FT4 where the results do not consistently comply with the quality assessment range. Depending on how the two-point calibration curve is applied, up to 5 test tubes can be conserved per test, and the reduced time for reagent dispensing is anticipated to have a positive effect on the TAT (turnaround time).