A LOW-NOISE ELECTROMETER FOR AN AUTOMATED OEC MEASUREMENT SYSTEM

测量血红蛋白氧平衡曲线（OEC） 在自动化系统中受到电子噪声的阻碍。 可靠的分压测量，精度 0.001 mmHg需要特殊的电子电路技术 设计 p02和pC02电极具有非常高的内部电阻， 电阻具有非常低的输出信号电平。 当这些 器械在受以下物质污染的环境中使用 射频干扰（RFI）， 步进电机的磁场或电力线瞬态 由大电流水浴产生，电极输出 引线必须保持短和屏蔽。 电极信号 必须通过计算机控制的信号保持缩放和偏移 处理器将这些测量的电压适当地接口到 AT型个人计算机，用于进一步的软件分析。 另一项任务是设计和制造所需的电路， 自动化系统的发展，使所需的 测量.

Measurement of the hemoglobin oxygen equilibrium curve (OEC) in an automated system is hampered by electronic noise. Reliable measurement of partial pressures with an accuracy of 0.001 mmHg requires special techniques in electronic circuit design. The p02 and the pC02 electrodes have very high internal resistance with very low output signal levels. When these devices are used in an environment contaminated by radiofrequency interference (RFI) from a computer, the magnetic fields of stepping motors, or power line transients generated by a high current water bath, the electrode output leads must be kept short and shielded. The electrode signals must be kept scaled and offset by a computer-controlled signal processor that interfaces these measured voltages properly to an AT-type personal computer, for further software analysis. Another task is design and fabricate the required circuitry for the development of the automated system to make the required measurements.