Meteorological Instrument Performance Characteristics

Instrument Performance Characteristics

Instrument performance characteristics can be described as static, conditions where the measurand is constant or slowly varying, or dynamic, where the input to a sensor changes rapidly.

Static performance characteristics are generally determined during instrument calibration, which is a comparison of measurement values with a calibration standard of known uncertainty. Static performance characteristics include the range, span, resolution, static sensitivity, linearity, and stability - plus peculiarities such as hysteresis and sensor threshold.

Every instrument comes with technical specification information (see the example Technical Data for the Vaisala RS41-SGP radiosonde) that describes the static performance characteristics. Technical specifications also include the time constant, which is the time that it takes for an instrument, after a sudden change in measurand value, to reach more than 63 percent of the new value. The time constant is a dynamic performance characteristic that will be discussed later in greater detail.

Technical Data for the Vaisala RS41-SGP radiosonde

Technical Data for the Vaisala RS41-SGP radiosonde. Image from Vaisala.