研究二氧化錫酸鹼感測器之非理想效應及校正方法

Study on the Non-ideal Effect of the Tin Oxide pH Sensor and the Calibration Method

蔡居能(Chu-Neng Tsai)

指導教授 ： 熊慎幹

中原大學/工學院/電子工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500306

摘要

pH值係最常見之量測，許多化學或生化反應皆仰賴pH值，且最佳之反應係受溶液的pH值所控制，故感測特性如靈敏度、時漂與遲滯係酸鹼感測器之決定因子，時漂與遲滯之現象係由慢響應所引起，於量測上造成誤差，故需瞭解非理想之效應及找尋適當的校正方法，改善非理想之現象。
本論文係以濺鍍法製作電壓式固態二氧化錫酸鹼感測器。研究元件之感測面積與感測膜膜厚對感測特性之影響，而二氧化錫酸鹼感測器合適之感測面積介於2 * 2 mm2與3 * 3 mm2之間，合適之感測膜膜厚介於230 nm與260 nm之間。
藉由時間常數模型研究二氧化錫酸鹼感測器之時漂與遲滯，且以時間常數模型模擬時漂之行為，於本論文中提出時漂校正之方法，此方法係實現於電路上，依研究結果，此時漂校正電路可校正二氧化錫酸鹼感測器之時漂，此外，結合時間常數模型及網路分析之觀念，連繫時漂與遲滯之關係後，可由時漂之時間常數模型預測遲滯之寬度。

關鍵字

時間常數模型 ； 時漂校正方法 ； 遲滯 ； 時漂 ； 電壓式固態二氧化錫酸鹼感測器

並列摘要

pH is one of the most common measurements because many chemical and biological processes are dependent on the pH. It is so important that the optimal reaction is controlled by the pH of the solution. Thus, the sensing properties such as sensitivity, drift and hysteresis are the decisive factors of pH sensors. The phenomena of the drift and the hysteresis result from the slow response and cause an error on the measurement. It is necessary to understand the non-ideal effect and find out the calibration method to improve the non-ideal phenomena.
A potentiometric solid-state SnO2 pH sensor prepared by sputtering method is studied in this study. The sensing area and sensing thickness are studied on the sensing properties. The suitable sensing area of the SnO2 pH electrode is between 2 * 2 mm2 and 3 * 3 mm2 and the suitable sensing thickness of the SnO2 pH sensor is between 230 nm and 260 nm.
The phenomena of the drift and the hysteresis of the SnO2 pH sensors are investigated by the time-constant model. The time-constant model is utilized to simulate the behavior of the drift. Furthermore, a method of the drift calibration is presented and the method is performed on the circuit. The experimental results indicate that the circuit of the drift calibration is efficient to calibrate the drift of the SnO2 pH sensor. Besides, the relationship between the drift and the hysteresis is linked by the time-constant model and the concept of the network analysis. In this way, the hysteresis width is predicted by the time-constant model of the drift.

並列關鍵字

potentiometric solid-state SnO2 pH sensor ； hysteresis ； drift calibration method ； drift ； time-constant model

參考文獻

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