sensitivity (redirected from sensitivity test)

sensitivity [‚sen·sə′tiv·əd·ē]

(electronics)

The minimum input signal required to produce a specified output signal, for a radio receiver or similar device.

Of a camera tube, the signal current developed per unit incident radiation, that is, per watt per unit area.

(engineering)

A measure of the ease with which a substance can be caused to explode.

A measure of the effect of a change in severity of engine-operating conditions on the antiknock performance of a fuel; expressed as the difference between research and motor octane numbers. Also known as spread.

(geology)

The effect of remolding on the consistency of a clay or cohesive soil, regardless of the physical nature of the causes of the change.

(physiology)

The capacity for receiving sensory impressions from the environment.

(science and technology)

The ability of the output of a device, system, or organism to respond to an input stimulus.

Mathematically, the ratio of the response or change induced in the output to a stimulus or change in the input.

---

Sensitivity (engineering)

A property of a system, or part of a system, that indicates how the system reacts to stimuli. The stimuli can be external (that is, an input signal) or a change in an element in the system. Thus, sensitivity can be interpreted as a measure of the variation in some behavior characteristic of the system that is caused by some change in the original value of one or more of the elements of the system.

Sensitivity is commonly used as a figure of merit for characterizing system performance. As a figure of merit, the sensitivity is a numerical indicator of system performance that is useful for predicting system performance in the presence of elemental variations or comparing the relative performance of two or more systems that ideally have the same performance. In the latter case, the performance of the systems relative to some parameter of interest is rank-ordered by the numerical value of the corresponding sensitivity functions. If T is the performance characteristic and X is the element or a specified input level, then mathematically sensitivity is expressed as a normalized derivative of T with respect to X.

A limiting factor in using the sensitivity of a system to characterize performance at low signal levels is the noise. Noise is a statistical description of a random process inherent in all elements in a physical system. The noise is related to the minimum signal that can be processed in a system as a function of physical variables such as pressure, visual brightness, audible tones, and temperature.

There exist many situations where the sensitivity measure indicates the ability of a system to meet certain design specifications. For example, in an electronic system the sensitivity of the output current with respect to the variation of the power-supply voltage can be very critical. In that case, a system with a minimum sensitivity of the output current with respect to the power-supply voltage must be designed. Another example is a high-fidelity audio amplifier whose sensitivity can be interpreted as the capacity of the amplifier to detect the minimum amplifiable signal.