Which sensor to choose?

Hi Jonas87,

You want a sensor which detects explosion right?

What about using image processing for this?

Here are some links of research papers which involve spectroscopy or laser based detection of explosives.

http://www.springerlink.com/index/212344k64558633r.pdf

http://adsabs.harvard.edu/abs/2009SPIE.7303E..61S

Missouri S&T Research - Sensor data fusion for spectroscopy-based ...

http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&ident...

Hi!

I have a relative low budget on my project...so wonder if it is possible to

use an ir-sensor at that range in daylight?

Thanks

Jonas

We can make simple smoke detector using the idea of change in light intensity which can directly alter the resistance of LDR.
When smoke passes between a bulb (or lightsource) and an LDR, the amount of light falling on the LDR decreases. This causes the increase in resistance of LDR and the voltage at pin 2 of IC 555 goes below 1/3 Vcc, thus triggering IC 555 which is used here in bistable mode. As a result the voltage of pin 3 goes high. This high voltage (approximately +9V) completes the supply to the COB (chip-on-board). Different COBs are available in the market to generate different sounds. However, one may select a COB which generates sound such as 'Siren'. The signal generated by COB is amplified by an audio amplifier. In this circuit, the audio power amplifier is wired around IC TDA 2002. The sensitivity of the circuit depends on the distance between bulb and LDR as well as setting of preset VR1. Thus by placing the bulb and the LDR at appropriate distances, one may vary preset VR1 to get optimum sensitivity. Reset switch S1 is provided in the circuit to switch off the alarm after the smoke has been noticed by the user.

Before implementing this idea read the datasheets and usage of various ICs used in the circuit or simply use the change of resistance of LDR to develop your own logic circuit. use mic and LDR together to detect an explosion.
Hope it helps.
PLease note that the intensity of smoke may cause very little variation in LDR, so dont forget to amplify output when you make your own logic circuit.