高壓量測用Manganin壓力計製程之改良

Abstract

Manganin電阻式壓力計是目前高壓，超高壓（＞7,000 atm）實驗中能作較精確壓 力量測的極少數直接式壓力計之一。其構成主要包括由Manganin細線捲繞而成的電阻線 圈，外接導線，捲線框架，和電阻量測儀等。壓力量測值的精確與否除與構成線圈的 Manganin細線本身的材質有密切的關係之外，製造時對線材所做的絕緣、退火、季化等 前處理和關於捲繞方式、框架材質等等也有直接的關係。 本研究中的Manganin壓力計經過纏繞、溫度季化、線圈之封裝和壓力季化的過程而 製作完成，並以直接加壓法校正Manganin壓力計。本實驗首先擬探討上述各加工條件下 電阻變化程度的大小，接著再求出Manganin壓力計電阻的壓力係數。本研究著重於探討 各種製程對起始電阻的偏移，壓力──電阻變化關係之一致性的影響，使用各種方法來 固定電阻線，再配合實驗條件的組合，歸納得出Manganin壓力計之最佳製程。 (1)線圈之纏繞：利用繞線機纏繞5mm電木棒，(2)溫度季化：48小時於矽油中，1小 時於液態氮中，(3)線圈封裝：使用香乳膠封裝線圈，(4)壓力季化：加壓一次30分鐘到 8000∼10000kg╱cm2，(5)固定壓力計。

Manganin resistance pressure gauge is one of the very few precision gauges used directly in the very high pressure (＞7000atm) application. It is composed of a manganin coil, coil structure, lead wire, resistance measure intrument. Precision of the pressure gauge depends not only on the material properties of the manganin, but also on the insulation of the wire, nealing of coil, seasoning procedures of the wires. Very often, methods of measurement of resistance, coil structures materials also play an important role on the precision of resistance value. Manganin pressure gauges used in this study are processed by temperature and pressure seasoning, coil sealing, and the fixation of pressure gauge. Then, calibration are conducted by direct pressing. Mariations of resistance under pressure, pressure coefficients of manganin are discussed. The purpose of this study is to find out the effect of initial resistance drifting on the relationship between pressure and resistance. Serious ways of fixing resistance wire have been tried. Followings are proposed manufacturing procedure for manganin pressure gauges. (1) winding: winding on the φ 5mm bakelite bar with the winding machine (2) temperature seasoning: 48 hour in silicon oil, 1 hour in LN2, (3) sealing: polyester, (4) pressure seasoning: keeping 30 minutes in 8000∼10000kg╱cm2, (5) firm fix of the pressure gauge in the lubricant.