Most people (myself included) tend to think of a sensor as having some specific active measurement component. So a biologically available dissolved oxygen sensor (BOD) (for instance) has a semi permeable membrane, and an electrode, and measures the change in conductivity in the region due to dissolved oxygen changing the ability to pass volts through purified water. (ok, this was the 70s. I have no idea how they work now) The point is you pump volts across a gap, the membrane changes how they flow. Voila! dissolved oxygen changes the resistivity, you get to read how much dissolved oxygen was in the sample.
But, the word is also applicable to a passive device if it can pick up a signal which can then represent a modulation of some other thing, through RF. The tip of a logic/IC probe, or a portable volt-amp meter in this instance is what they are calling the "sensor" when in fact, the sensor is the increadibly finely balenced coil and spring and magnet: the probe is just how the data comes in. (ok this is the 1890s. I have no idea how this works now)
It's an antenna system. The Electrode gap, in my BOD example, but sans volts. You have to add the volts. Either it injects and reads, or its read-only. its the tip of the probe. Its got no active elements. How it "reads" depends on how you can convert something under measurement into a signal which it can pick up. The actual "sensor" component might be somewhere else. This is the transducer which you attach to something.
I am guessing it can be used to make RFID antenna as well. That would be cool. Does anyone remember the sparkle gaps you got for the back of AMPS cellphones which lit up like a christmas tree when the 'wake up' signal was pumped into the phone?
Actually nowadays, a dissolved oxy meter is probably best known as a fingerclip LED reader, and measures things by shining a red LED at your flesh to pick up on some aspect of the blood flow in a finger. I don't see any selectively permeable membrane there, its using another effect to measure. Passive probe? well.. you do shine an LED. so theres a transducer involved..
But, the word is also applicable to a passive device if it can pick up a signal which can then represent a modulation of some other thing, through RF. The tip of a logic/IC probe, or a portable volt-amp meter in this instance is what they are calling the "sensor" when in fact, the sensor is the increadibly finely balenced coil and spring and magnet: the probe is just how the data comes in. (ok this is the 1890s. I have no idea how this works now)
It's an antenna system. The Electrode gap, in my BOD example, but sans volts. You have to add the volts. Either it injects and reads, or its read-only. its the tip of the probe. Its got no active elements. How it "reads" depends on how you can convert something under measurement into a signal which it can pick up. The actual "sensor" component might be somewhere else. This is the transducer which you attach to something.
I am guessing it can be used to make RFID antenna as well. That would be cool. Does anyone remember the sparkle gaps you got for the back of AMPS cellphones which lit up like a christmas tree when the 'wake up' signal was pumped into the phone?
Actually nowadays, a dissolved oxy meter is probably best known as a fingerclip LED reader, and measures things by shining a red LED at your flesh to pick up on some aspect of the blood flow in a finger. I don't see any selectively permeable membrane there, its using another effect to measure. Passive probe? well.. you do shine an LED. so theres a transducer involved..