Which expert knows what product the sensor button on the display of the E+H transmitter is?

There are many types of buttons; if you don’t want a mechanical design, you can choose electromagnetic or infrared ones

It seems that an electromagnetic version cannot be implemented. For the infrared type, I’m not sure whether to choose an active or passive version; it appears that E+H uses a passive version. There’s also the pyroelectric infrared sensor I found online; I’m not sure if it can perform accurate switching functions without being affected by interference signals

Some current field transmitters use magnetic switches, operated with magnets.

All infrared devices are passive; their principle involves a light-emitting diode and a photosensitive transistor – the packaging may differ, but the principle remains similar. To be honest, I’ve never used pyroelectric infrared sensors, but after doing some research on Baidu, I think they might be quite sensitive to temperature and subject to significant interference. However, adding a filtering capacitor at the sensor’s signal input terminal might help solve some of these problems. The function of the button sensor is to adjust settings; there’s no need for something overly sophisticated. As a user, I have to say that infrared buttons are either too sensitive or not sensitive enough. The high-precision mass flow meters used in our company (products from 10 years ago) have infrared buttons, which are of the simplest type – but they still work fine these days. For reference only

Thank you for your guidance; I now have some understanding of capacitive buttons. The infrared sensor type consists of a transmitter and a receiver, and its principle is similar to that of the distance sensor in smartphones. There is also a type of sensor button that uses magnetic induction; the advantage of this type of button is that it is less susceptible to interference. The downside is that a small magnet needs to be carried along every time parameters need to be set.