水氣量測對於現代工廠的設備儀器是需要被注意的，在無法得知儀器中濕度變化的情況下，可能會因為濕度的高低變化，使得儀器零件因此故障，所以需要準確的露點感測器來做量測。本研究目的為建構電容式聚合物露點計自動檢測以及線性化校正系統，系統包含PC控制器、自行開發之人機介面(HMI, Human Machine Interface)、實驗腔體、雙流量閥控制模組、露點感測器、標準源MBW973、露點計微處理器晶片模組、資料擷取模組、校正模型建立、通訊系統及線性補償系統。
本研究首先建構可控制露點量程之實驗腔體，再將露點感測器安裝於實驗腔體中，進行露點的量程檢測與校正。由PC端透過DAQ卡輸出電壓控制雙流量閥以控制腔體濕度(-60℃~20℃)，藉由冷鏡面式露點儀MBW 973作為參考標準源及回授。本研究運用伺服回授控制乾、濕空氣的流量控制閥，來達到低露點至高露點的混流量測。其中極高與極低露點必須考慮到流量閥所能控制的流量輸出範圍，與乾空氣的輸出量匹配，並參考IEC 61298-2規範完成晶片在不同濕度下之輸出訊號檢測。再將計算出其訊號對應露點的曲線係數利用Modbus寫回露點感測器STM32F微處理器晶片中，完成露點計線性化校正。最後透過自動品質檢測系統，設定各人機介面參數與標準參考源參數，再次進行露點感測器的品質檢測，如誤差、重現性、遲滯性等並記錄與輸出品管及校正報表，完成品質檢驗。
本研究透過自動量程實驗設計，建立了乾濕控制閥輸出匹配與回授機制，完成露點測試腔體之流量控制參數。各量程的目標露點藉由伺服回授控制皆可以使腔體達到所要求的準確度範圍內，其準確度最高可以達到±1℃的範圍。由實驗數據顯示，檢測樣本A的各量程平均誤差將可控制在2%以內，確實能有效改善露點計的穩定度與精確度。

The moisture measurement is very important for modern factory's equipments. If the humidity in an instrument can not be measured, the equipments may be failed because the humidity is changed too much. Therefore, a precise hygrometer is necessary for the humidity measurement. The purpose of this study is to construct a quality inspection and linearization calibration system for Capacitive Polymer Hygrometers (CPH). The system consists of a host PC with self-developed Human Machine Interface, a humidity controlled chamber, two mass flow control modules, a hygrometer, a standard MBW973, a microprocessor chip module, an automatic data acquisition module, a linear calibration model, communication and compensation systems.
To process a dew point span measurement and calibration, a hygrometer is installed in a humidity chamber. Two mass flow meters are controlled with a DAQ module from the host PC, and a Dew Point Device (MBW973) is worked as a standard reference / feedback. This study uses servo feedback technique to control both the dry and wet mass flow meters to reach the required ranges of dew point (-60℃~20℃) with mixing flow measurement. The highest and lowest dew point measuring must consider the exact output range of dry and wet mass flow meters, and the output signal is measured under different humidity by the microprocessor chip based on IEC 61298-2. The main system calculates polynomial mathematical coefficients from the signal corresponding to the dew point automatically, and the coefficients are saved into the STM32F based CPH via Modbus. After the automatic data acquisition system with HMI parameter setting, the inspected functions of CPH include error percentage, repeatability and output quality reports from the system.
By following the automatic span experiment design, an output matching combination of dry and wet mass flow meters is established. It enables more accurate control of the required dew point in humidity chamber with function feedback. In each span, the servo feedback technique is used to control the dew point in a certain range, in which the best accuracy within ±1℃can be achieved. From the experimental results, the average error from each span of Sensor-A has been maintained within 2%, and the accuracy and stability of a hygrometer can be improved.

[1] F. Reverter, Ò. Casas , “Direct interface circuit for capacitive humidity sensors”, Sensors and Actuators A: Physical, Vol. 143, No. 2, pp. 315-322, 2008.
[2] G. Gong , C. Xu , J. Jiao , Y. Liu , S. Xie, “Investigation of moisture condensation on papermaking plant envelopes in high humidity environment by orthogonal analysis and CFD simulation”， Building and Environment 46 (8), pp. 1639-1648,2011.
[3] 上海卓盼電子科技有限公司http://www.zhope17.com/pdlistone/tech/420515.html, 2011.
[4] 馮丁樹，「濕空氣之特性」，國立台灣大學生機系，2001。
[5] 陸紀文，「冷凍空調原理講義 第十二節、濕空氣線圖及其應用-2」，國立勤益技術學院冷凍系，2005。
[6] 上海適科暖通機電設備科技有限公司 http://www.siko-ins.com/zh-tw/s04/siko-ins/cgal/20100920/17002.html ,2008.
[7] 頤拓企業有限公司， http://www.etorch.com.tw/TechnicalData.htm,2009.
[8] American Society of Heating, Refrigerating and Air-Conditioning Engineers, ASHRAE Handbook Fundamentals (I-P edition), Inc. New York, 1993.
[9] Digiquartz Dew Point Calculation，http://www.paroscientific.com/dewpoint.htm
[10] Lawrence, Mark G., "The Relationship between Relative Humidity and the Dew point Temperature in Moist Air: A Simple Conversion and Applications", Amer. Meteor. Soc., Vol. 86, No. 2, pp. 225–233, February 2005.
[11] 相對濕度、露點及溫度關係式http://www.ajdesigner.com/phphumidity/dewpoint_equation_dewpoint_temperature.php
[12] 陳福春，感測與轉換器(三版)，高立圖書，2004。
[13] 谷腰欣司，感測器セソサ一のレくみ，全華圖書，2006。
[14] 周佳德、蔡明忠、朱仁誠，「溫濕度感測器自動化品管檢測系統研發」，機械月刊，七月號，第444期，2012.
[15] Wiederhold, P. R., “Water vapor measurement”, Marcel Dekker, Inc. ISBN: 0-8247-9319-6, pp. 70-81,159,160, 1997.
[16] 陳加忠，“電阻式相對溼度計之校正與性能研究”，興大工程學報( 2 ) ：pp.61-68,1998。
[17] 陸慈宏，”相對溼度計校正與量測不確定度之研究”，碩士論文，國立中興大學生物產業機電工作學系 ，2003。
[18] 黃榮彬，”相對濕度計利用於畜舍環境之評估”，碩士論文，國立中興大學農業機械工程學系 ，2000。
[19] 陳加忠、賴建洲、曹之祖，“電子相對濕度計之性能評估”，中華農業研究40 ( 1 ) ：pp.71-89,1991。
[20] 陳加忠、曹之祖，“相對溼度計標準校正裝置之製作試驗”，中華農業研究 41 ( 4 )：pp.371-381,1992。
[21] Milosevic, Nenad D., Stepanic, Nenad M., Babic, Marijana M. “A Relative Humidity Calibration From 5 degrees C to 45 degrees C in a Mixed-Flow Humidity Generator”, Thermal Science, Vol. 16, No. 1, pp. 193-205, 2012.
[22] Bob Hardy, “Trust but verify-practical approaches to humidity generation and measurement,” RH System, Albuquerque, NM, USA Copyright 2000.
[23] M. NADI, C. MARGO, M. KOUIDER, J. PRADO, and D. KOURTICHE, "Embedded system design and implementation of standard auto-calibrated measurement chain", INTERNATIONAL JOURNAL ON SMART SENSING AND INTELLIGENT SYSTEMS, VOL. 1, NO. 1, MARCH 2008.

[24] GERT VAN DER HORN, JOHAN H. HUIJSING, "Integrated Smart Sensor Calibration", Analog Integrated Circuits and Signal Processing, Vol. 14, No. 3, pp. 207-22, November 1997.
[25] 林惠玲、陳正倉，應用統計學(四版)，雙葉書廊，2009。
[26] 南希,龔龍慶,田衛,李瀟,”基于FPGA的動態可重構系統設計與實現”, MODERN ELECTRONICS TECHNIQUE, 2009
[27] W M. Humphrey，基本伺服機構系統設計，科技圖書，1991。
[28] Franklin, Powell, Emami-Naeini，動態系統回授控制，曉園出版社，1988。
[29] 黃建榮，”網路電力監控系統之設計與製作”，碩士論文，逢甲大學資訊電機工程碩士在職專班， 2006。
[30] 黃煌翔，介面技術與週邊設備（修訂版），全華圖書，2004。
[31] Modbus.Org, http://www.modbus.org.
[32] Modbus Tools http://www.modbustools.com/modbus.asp
[33] 張偉強，”利用 Modbus RTU結合遠端處理技術之監控系統設計”，碩士論文，中國文化大學工學院數位機電科技研究所， 2010。
[34] IEC International standard,“IEC 61298-2:E2 PROCESS MEASUREMENT AND CONTROL DEVICES –GENERAL METHODS AND PROCEDURES FOR EVALUATING PERFORMANCE –Part 2: Tests under reference conditions”, 2008.
[35] 中華人民共和國國家質量技術監督局，「GB/T 18271.2-2000過程量測和控制裝置通用性能評定方法與程序 第2部分:參比條件下試驗」，2001.
[36] IST，http://www.ist-usadivision.com/company/
[37] MBW 973，http://www.mbw.ch/product_973.php
[38] 研華科技Advantech，http://www.advantech.com/，2011.
[39] Vogetlin，http://www.voegtlin.com/index_en.html

[40] 宇田控制科技股份有限公司,“乾溼空氣混和之露點量測專案期末報告”, Jan 2013.
[41] 宇田控制科技股份有限公司，http://www.yuden.com.tw/，2013
[42] 惠汝生，LabVIEW 8.X 圖控程式應用，全華圖書，2006。