Photoelectric sensor and method for aiding checking of threshold

A method for aiding checking whether or not a threshold set for a photoelectric sensor is appropriate, the photoelectric sensor including:

• a light-projecting unit for projecting light;
• a light-receiving unit for receiving light projected from the light-projecting unit and generating data on an amount of received light;
• an output unit for outputting a detection signal indicating that a detection target has been detected;
• a signal processing unit for receiving the data on the amount of received light generated by the light-receiving portion, performing a measuring process for the data on the amount of received light, comparing measurement data obtained by the measurement process with a predetermined threshold to determine whether a detection target is present or not, and switching between ON and OFF states of the detection signal according to a result of the determination;
• and an input unit for inputting a set value for the threshold,
• the method comprising:
• causing the photoelectric sensor to measure a length of a measurement data change period which is from when measurement data at a level at which the detection signal is off starts to change in a direction of the threshold to when the measurement data returns to a level at which the measurement data started to change;
• causing the photoelectric sensor to measure a length of an ON-period for which measurement data at a level at which the detection signal is on is obtained during the measurement data change period;
• on the basis of a relationship between the lengths of the measurement data change period and the ON-period, displaying information on the length of the ON-period and on a margin for the measurement data change period with respect to the ON-period on a display unit provided integrally with the photoelectric sensor or on an external display provided for the photoelectric sensor.