压力传感器的功能与技术

A pressure sensor includes several main components. A pressure sensor consists of a measuring diaphragm deforming at changing pressure, an opening for pressure intake, various sensor elements (e.g. piezoelectric, capacitive or piezoresistive), a signal processing unit for signal amplification and processing, a protective housing as well as electrical and mechanical connections for connectivity to external devices. These components interact to provide precise pressure measurement results in various applications.

Basically, there are different pressure sensor types based on different measuring principles:

• Resistive pressure sensors measure pressure by change in the electrical resistance resulting from mechanical stress imposed on a material.
• Piezoelectric pressure sensors generate electrical voltage through charge displacement in piezoelectric material under pressure.
• Capacitive pressure sensors detect changing capacitance in a capacitor caused by membrane deformation.
• Inductive pressure sensors measure pressure by changing coil inductance at moving a magnetic core or membrane.
• Pressure sensors with Hall element use the Hall effect to measure pressure changes.
• MEMS pressure sensors use micro-mechanical structures on a silicon chip to measure pressure.

Baumer has specialized in the common resistive pressure sensors and piezoresistive pressure sensors. Here you encounter the Baumer pressure sensors.

• “零点温度系数”用于描述温度对零点以及精度的影响。
• “满量程温度系数”用于描述温度对满量程点以及精确度（即标准测量误差）的影响。
• 零点温度系数和满量程温度系数合起来表示温度对最大测量误差的影响。

温度对最大测量误差的影响

在大多数情况下，如果工作温度偏离了参考温度（例如20 °C），应首选精度较低但具有较高温度稳定性的传感器，而非精度较高但温度稳定性不高的传感器。

误差定义

堡盟规定了产品的“最大误差定义”，即从统计角度看，保证99.7%的堡盟传感器符合技术规格。部分竞争对手的产品采用“典型误差定义”，即他们有32%的产品不符合技术规格

高温蒸汽常用于各种装置和设备的灭菌。传感器（如PBMH高压灭菌型）等小尺寸压力传感部件，可在适当的容器（如高压灭菌型蒸锅）中灭菌。对于大型装置，可将高温蒸汽导入整个系统，即所谓的“现场灭菌”（SIP）。因此，尽管在灭菌过程中传感器通常不会传输信号，但它必须设计得很坚固耐用，能够承受灭菌过程中常见的温度和压力（例如：温度134 °C，压力3 bar，持续时间30分钟）。从物理角度来说，压力和温度直接相互影响，如以下饱和蒸汽曲线所示。

堡盟PBMx和PFMx压力传感器是控制灭菌过程的理想选择。即便在温度变化很快的情况下，它们也可以提供准确的测量值。这样，根据温度和压力的对应关系，通过监控压力就能实现可靠的过程控制。