FD223A  雙通道差分靜電計
Dual Channel Differential Electrometer
型號： FD223A

• 高輸入阻抗。
• 差分(A-B)輸出。
• 低噪音、大頻寬。
• 電極電阻測試電路。
• 包含2個1015 Ω 阻抗探頭。

Reference

E. Ermolayeva, H. Hohmeyer, E. Johannes, D. Sanders "Calcium-dependent membrane depolarisation activated by phytochrome in the moss Physcomitrella patens" Planta 199. 1996: 352-358

特色

FD223A雙通道差分、高阻抗放大器/靜電計，特別針對離子特異性（K+、Na+、Cl-等）和pH電極的電化學測量所設計。此裝置非常穩定無飄移，內建規則用於測量和調整輸入漏電流。DC Level可獨立調整每個探針通道。

克服噪音

一般由長電纜將測得電位帶入儀器，FD223A具直接在測量點定位傳感探針的能力，可克服由長電纜引入的噪音。探針輸入的訊號驅動保護器維持特定高電阻並減少探針的雜散電容。細心的設計，加上高品質的組件選擇，尤其是探頭（headstage），成就具有大頻寬的優越放大器。FD223A忠實再現測量訊號。為減少噪音和雜散電容，更進一步地探頭殼體包含一個訊號驅動保護器。內部驅動外殼在探頭尖端暴露一部分，允許彈簧護罩於電極固定器和微電極延伸。

探頭測試端口

放大器具探頭測試端口，允許電極測試和設定電極漏電流（IG)。待機模式，當玻璃微電極或電極固定器接上探針輸入。在待機模式下，探針輸入的電壓鉗制接近0伏特，從而保護輸入。

 規格

Details

The FD223a is a dual channel differential, high impedance amplifier/electrometer designed specifically for electrochemical measurements using ion specific (K+, Na+, C1-, etc.) or pH electrodes. The instrument is very stable, drift free, and features a built in provision for measuring and adjusting input leakage current. DC levels may be independently adjusted for each probe channel.

Overcoming noise

The ability to locate the sensing probes directly at the measurement site overcomes the noise introduced by the long cables usually needed to bring the measured potential to the instrument. Signal-driven guards at the probe input maintains the specified high resistance and reduces the stray capacitance of the probes. Careful design, coupled with quality component selection, particularly in the headstage, results in an excellent amplifier with low noise and wide bandwidth. The FD223a will faithfully reproduce the measured signal. To reduce the noise and stray capacity even farther the probe housing includes a signal driven guard. A portion of this inner driven shell is exposed at the probe tip allowing a spring shield to be extended over the electrode holder and microelectrode.

Probe test port

The amplifier features a probe test port that permits testing of the electrode test feature and setting of the probe leakage current, (IG). A standby mode is included and should be used when attaching glass microelectrodes or electrode holders to the probe input. While in the standby mode the voltage at the probe input is clamped near zero volts thus protecting the input.