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Research paper : Improvement of reliability in pressure measurements and international mutual recognition (T. Kobata et al.)−220−Synthesiology - English edition Vol.4 No.4 (2012) the client takes the pressure gauge from the usage site to the calibration lab. However, for the pressure standard to be used in a wider range of industrial fields, it is necessary to consider a more efficient, new ways of providing the standard. In the NEDO Project “Technology Development for an ‘e-trace’ System”, the remote calibration technology for pressure was developed to provide the pressure standard quickly, at low cost, and accurately, by utilizing the digital pressure gauge and the information technology such as the Internet[26][27]. This was a technological development that allowed the calibration of the pressure gauge at the industrial sites without moving it from the industrial site to the far away calibration lab, and was a new form of providing the pressure standard to reduce the burden on the calibration client.Currently, when the calibration labs conduct calibration by request from the clients, the calibration can be roughly divided into three forms: carry-in calibration, dispatch calibration, and remote calibration. The major characteristics of each calibration form are shown in Table 2.In the traditional carry-in calibration, the calibration is done as the client brings the pressure gauge to the calibration lab. In this case, the standard device of the calibration lab is used, and the work is done by the personnel of the calibration lab. When it is impractical to transport the client’s pressure gauge to the lab, the calibration is done at the place where the pressure gauge is installed. The calibration done outside of the calibration lab is the dispatch (on-site) calibration. In this case, the transportable standard device (transfer device) is transported from the calibration lab to the site. The calibration work is done by the personnel of the calibration lab, as in the case of carry-in calibration.In remote calibration, calibration is done by sending the transfer device to the place where the client’s pressure gauge is being used, as in the dispatch calibration. However, the calibration lab personnel does not go to the site, and the calibration work is done by exchanging the measurement data via communication technology such as the Internet from the calibration lab. This point is different from the dispatch calibration. It is assumed that the client’s pressure gauge (device under calibration) is a digital pressure gauge. The supporting personnel at the client company attends a technical seminar to do the work of installing the device under calibration and the transfer device, as this will not greatly affect the calibration result.Figure 9 shows the procedure for remote calibration of pressure. It shows an example of the process where the client makes a request for remote calibration to the calibration lab. In this figure, the area surrounded by dashed line and marked “Internet” is the part that can be accomplished via the information network technology.The development of the remote calibration technology was done for the two pressure ranges (gas differential pressure of 10 Pa ~ 10 kPa and hydraulic pressure of 10 MPa ~ 100 MPa) for which the performance of the digital pressure gauge has been proven in the past international comparisons, and where there was high demand for calibration from industry. Technological collaborations were obtained from Yokogawa Electric Corporation for the development of gas differential pressure, and Nagano Keiki Co., Ltd. for hydraulic pressure. The main items of development were as follows:(1)Development of transfer device for remote calibration(2)Development of measurement procedure applicable for remote calibration(3)Execution of demonstration experiment in Japan and overseasFor Item (1), the portable transfer device for remote calibration was newly developed by incorporating the high-precision digital pressure gauge, pressure generator, and environmental Fig. 9 Execution procedure for remote calibration for pressure InternetCalibration labClientApplication for calibrationSend transfer deviceReturn transfer deviceIssue calibration certificateTransmit measurement dataStandard device Device under calibrationFull automatic calibrationInternetTransfer deviceInternet1.2.3.4. 5.(used for calibration of transfer device)Table 2. Form and characteristic of the calibration of pressure gaugeRemote operation, support personnelLab personnelLab personnelCalibration workTransfer device (transfer standard)Transfer device (transfer standard)Reference standardStandard deviceClient-designated placeClient-designated placeCalibration labPlace of calibrationRemote calibrationDispatch calibration (on-site calibration)Carry-in calibrationCalibration form

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