There is a plethora of devices aimed at very narrow markets. If you aren’t in that market you will never use one of those devices.
Every now and again you may be asked to measure or control some phenomenon that is outside your expertise and may require considerable research and development. Isn’t it nice to discover that there are many niche products that meet that and only that need?
I once developed the controls for a sprinkler system in an aircraft hangar. Because the fire-quenching foam is corrosive, the customer didn’t want lightning activity in the area to trigger a false alarm and unnecessarily damage expensive aircraft parts. At the time we had to buy an expensive stand-alone product, but today there is a chip just for the purpose- the AS3935 Franklin Lightning Sensor IC.
Natural gas can have water vapour mixed in with it. When pressurised, the water vapour condenses and rusts the metal container. This is considered a BAD thing and so I was detailed with creating a dryer technique to heat the gas and get rid of the water. It would have been convenient to measure the relative humidity but at the time specialized ICs were not available and the available sensors were not that accurate.
Now there seem to be a few, all of which include a temperature sensor. There are some Honeywell offerings that are available both in analog and digital outputs. Servoflo carries a series of devices for measuring humidity. Silicon Labs produce a range of humidity sensors some of which have quite good accuracy specifications. Sensirion is yet another provider of humidity sensors.
Associated with relative humidity is the dew point, and yes there is a sensor for that, also available from Servoflo.
Want to measure dust? I never have, but just in case there is the Amphenol Telaire Dust Sensor. Whilst we are yakking about air quality if you need to measure Volatile Organic Compounds in the air, Austrian Microsystems (ams) offers this device.
And do you need to know light intensity? Austrian Microsystems (ams) (they seem to specialise in all these niche products) has just the item for you, digital interface and all.
When it comes to measurement of location and movement there has been an explosion of devices as a result of the mobile phone/tablet phenomenon. Still you may need to measure wind speed. Try this device.
Do you know what a variometer is? Me neither. It appears to be a form of altimeter i.e. it measures air pressure- here’s a miniature one: MS5805-02BA01. I don’t want this to turn into an advertorial for Servoflo, but they do carry an interesting selection of products and if you need to sense anything, it might be a good idea to look at their range. Austrian Microsystems (ams) fall into the same boat. For example, there is device that senses the angle of rotation of a magnet on an axis.
TI produces a bunch of sensors and Mouser have collected and presented them in an easily accessible web page. ‘Nuff said.
The concept of “time of flight” appears to mean different things to different manufacturers. Depending on what it means to you the following devices may have a purpose in your world: the Leddar product range, TI’s TDC2700 or ST’s VL6180X.
Have your eyes started to glaze over yet? The product range from Excelera doesn’t believe in false modesty. One is called a “Universal Sensors and Transducers Interface” and another “Universal Frequency-to-Digital Converter”. You can find a description in their catalog. The data sheets are here along with an application note.
I hope that this array of products elicited at least one “wow” from each of you. More than that I hope it actually gave you some idea of a device you can use in an upcoming project. You may never need a spectrometer but you can rest easy that there are several if the need ever arises. I am sure I missed many other exotic devices- please add to the list in the comments below.