甩尾测痛仪测量大鼠对辐射能反应时间，辐射来自150瓦光源。甩尾测痛仪使用一台抛物面反射器将射线集中于大鼠尾。光源的能量可以调节并能够显示能源利用的百分率。为镇痛药物疗效迅速出现多使用大鼠.

This meter measures a rat’s reaction time to radiant energy,from a 150 watt light source. The beam is focused on its tail usinga parabolic reflector. The energy of the light source can beadjusted and the display indicates, as a percentage, how muchenergy is being utilized
For rapid screening of analgesic drugs usingrats (as described by D’Amour and Smith)


An opticalsensor is located underneath the focused light source. The ratshould be positioned such that its tail obscures the focused lightsource from the sensor. When the system is started, either usingthe supplied footswitch or front panel mounted start key the lightsource illuminates and a timer starts counting in tenths of asecond. When the rat’s tail flicks, indicating its pain threshold,it uncovers the sensor. This tail movement turns off the timer andlight source. Reaction time can be read directly from the displayin seconds and tenths of a second.
A standard parallel port permits connection to a printer to recordthe trial number, energy level and reaction time. A calibrationfacility allows the light source to be set to the desired levelbefore commencing with the experiment.