A sensor used to monitor an external condition The condition itself is described in :ref:`NXenvironment`. Sensor identification code/model number Name for the sensor Short name of sensor used e.g. on monitor display program where sensor is attached to ("sample" | "can") Defines the axes for logged vector quantities if they are not the global instrument axes name for measured signal The type of hardware used for the measurement. Examples (suggestions but not restrictions): :Temperature: J | K | T | E | R | S | Pt100 | Rh/Fe :pH: Hg/Hg2Cl2 | Ag/AgCl | ISFET :Ion selective electrode: specify species; e.g. Ca2+ :Magnetic field: Hall :Surface pressure: wilhelmy plate Is data collection controlled or synchronised to this quantity: 1=no, 0=to "value", 1=to "value_deriv1", etc. Upper control bound of sensor reading if using run_control Lower control bound of sensor reading if using run_control nominal setpoint or average value - need [n] as may be a vector Nominal/average first derivative of value e.g. strain rate - same dimensions as "value" (may be a vector) Nominal/average second derivative of value - same dimensions as "value" (may be a vector) Time history of sensor readings Time history of first derivative of sensor readings Time history of second derivative of sensor readings For complex external fields not satisfied by External_field_brief