E3T - FD11/FD13

• Type1: Both are diffuse - reflection - type infrared sensors. The E3T - FD11 is a flat - type sensor, and the E3T - FD13 belongs to the same series with similar functions but may have differences in some specific parameters or installation methods.
• Detection range3: The detection distance of the E3T - FD11 is 5 - 30mm. There is no specific information on the detection range of the E3T - FD13, but it is presumably within a similar range.
• Electrical characteristics: They usually have NPN or PNP output forms to meet different circuit connection needs1. For example, the E3T - FD11 has an NPN - output type, which outputs a low - level signal when detecting an object and a high - level signal in the absence of detection.

E3T - ST12/ST22

• Type: These are through - beam photoelectric switch sensors3. The E3T - ST12 and E3T - ST22 have similar structures and functions, but there may be some differences in details such as size, shape, and pins.
• Detection range: There is no specific detection - range data provided for these two models. However, as through - beam photoelectric switches, they generally have a longer detection distance than diffuse - reflection - type sensors, usually ranging from several centimeters to several meters.
• Working principle: The through - beam photoelectric switch consists of a transmitter and a receiver. The transmitter emits infrared light, and the receiver receives the infrared light. When an object blocks the infrared light path between the transmitter and the receiver, the receiver's received light signal changes, triggering an output signal change to indicate the presence of an object.