A LOW-NOISE ELECTROMETER FOR AN AUTOMATED OEC MEASUREMENT SYSTEM

全自动血氧平衡曲线的测定 系统受到噪音的阻碍。在部分阅读中获得可靠的结果 压力的精度为0.01毫米汞柱，需要特殊的技术 电子线路设计。P02、pH和PCO2电极有-非常 高内阻，输出信号电平非常低。当这些 设备使用在受无线电频率污染的环境中 来自计算机的干扰(RFI)，步进电机的磁场， 以及由大电流水浴产生的电力线瞬变， 电极输出引线必须保持短路和屏蔽。电极 信号必须通过计算机控制的信号保持定标和偏移 适当地将这些电压连接到AT型个人的处理器 计算机，用于进一步的软件分析。另一项要执行的任务是 开发所需电路的设计和制造 自动系统执行所需的测量。

Measurement of the hemoglobin oxygen equilibrium curve (OEC) in an automated system is hampered by noise. To obtain reliable results in reading partial pressures with an accuracy of 0.01 mmHg requires special techniques in electronic circuit design. The P02, pH, and the PCO2 electrodes have -very high internal resistance with very low output signal levels. When these devices are used in an environment contaminated by radio frequency interference (RFI) from a computer, the magnetic fields of stepping motors, as well as 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 properly interfaces these voltages to an AT-type personal computer, for further software analysis. Another task to be performed is the designing and fabrication of the required circuitry for the development of the automated system to perform the desired measurements.