Described is a method for reading an array of sensors having a set of row conductors each connected to the sensors in a corresponding row of the array and a set of column conductors each connected to the sensors in a corresponding column of the array such that each sensor is connected between a row conductor and a column conductor. The method comprises: for each row of sensors in the array, performing a read cycle comprising applying an activation pulse to the corresponding row conductor to activate the sensors in the row, applying a reading pulse to the row conductor on expiry of a predetermined time interval from an edge of the activation pulse, and during the reading pulse, detecting, for each sensor in the row, a value dependent on a variable characteristic of that sensor. The read cycle for at least one row is commenced during the predetermined time interval of the read cycle for another row. In a preferred example described in detail, the sensors are thermal resistance sensors, the activation pulse is a heating pulse to heat the sensors, and the variable characteristic is resistance.