Whistle detection-pressure cooker

Have been given a project to design a system which can set/count the number of whistles a pressure cooker gives out.The device has to be hanged on a wall near the pressure cooker.Have decided to use a humidity sensor to detect when the whistle is given out(as a pressure cooker will give out steam while whistling).Tried to use this http://www.8051projects.net/e107_files/public/1294408435_32030_FT42502_humidity_sensor.pdf
but calibration is being a pain..and i am not sure of the sensors range of detection..Is it sensitive enough to detect humidity changes when kept around a meter away from the cooker..what is it's reaction time..the data-sheet was not that helpful in that respect..I followed the instructions here
GY-HRTM203 humidity/temp sensor ... I can't make sense of the data sheet. - Sensors - Arduino Forum
but i am getting weird values and having a hard time with calibration..any ideas?..anyway to make the project simpler?..thought about acoustic sensors but again the range and cost comes into affect..

Maybe an IR sensor looking across the top of the cooker.

Pressure cookers are dangerous :wink:

Thought about that..but I am trying to think of it as a "product" going out in the market...and would like to give the user as less work as possible(setting up the IR will be a pain for ppl)...just hang the device near the wall...let it count...and display..:slight_smile:

humidity sensor

This would be hard to use since you have no control over the environment where you are installing the device.

I suppose an IR device could look at a sudden increase in the rate of change.

Ok…I’ll give it a go and lets see what happens…Ty…:slight_smile:

These might be of some help:

http://www.singh-ray.com/iray.html

I can already think of a few drawbacks/problems with this idea, but there might be a way to get it to work....?

What about a PIR sensor? Have a short delay before it kicks on so the person can get out of "sight" first. Obviously, there would be issues in a busy kitchen, or if someone walked by it...

Thought I'd throw it out there though.

Good luck!

Cool..thanks for the inputs...I'll keep you guys updated!! :slight_smile:

any ideas?..anyway to make the project simpler?..thought about acoustic sensors but again the range and cost comes into affect

Not clear on what you are trying to do. I've got two pressure cookers and neither whistle. What are you trying to monitor on the pressure cooker, internal pressure?

See the pressure regulator/vent weight in the pic…it releases pressure as the name says…it does that by letting out steam(kind of makes a whistling sound)…so in cooking, people relate the number of times the regulator releases pressure(whistle) to the food being cooked or otherwise…I want to make the whole process automated…the first step being to count the number of times the regulator releases pressure …hope that this makes it clear? :slight_smile:

It may be that cooking is done differently where you are, but here in the UK when using a pressure cooker (whistling or otherwise) the number of times the pressure cooker "lets off steam" while cooking is irrelevant - once it has built up pressure it will vent any excess pressure as needed, just as a simmering pan produces steam. What is important is how long the contents have been up to temperature, not how many times a valve let off steam along the way.

Wikipedia:

In other models, the pressure regulator weight begins levitating above its nozzle, allowing excess steam to escape. At this stage, the heat source should be reduced because heat is only needed to maintain pressure.[5] If the heat source is too high, then energy is wasted, too much liquid may be released to maintain the nominal pressure, and reduces the life of the gasket/sealing ring by wear.

My wife has never allowed me to utilize this particular kitchen appliance, of which we have two. Perhaps my sorted past experiments in creating sugar-rocket fuel in the home kitchen is responsible for my ban. In any event, the 'rocking motion' on both of the pressure cookers is specified in the manual in relationship to the external energy (flame/electric setting). The process starts with higher energy being applied and after the pressure is sufficient, energy is removed until a specified, rhythmic rocking motion is sustained. The 'whistle' effect sounds more to me like an old steam-piston train but I do not detect the higher frequencies in hearing well anymore.

I would build a small microphone amplifier and determine if it could be utilized with some filtering.

Optical interception of either the rocking or steam release seem very problematic for a 'fixed' sensor unit. A friend with an oscilloscope would be invaluable for such investigations. You may not succeed, but you should eat well during the experiments.

Ray

See the pressure regulator/vent weight in the pic...it releases pressure as the name says...it does that by letting out steam(kind of makes a whistling sound)..so in cooking, people relate the number of times the regulator releases pressure(whistle) to the food being cooked or otherwise...I want to make the whole process automated

pawankumar_urs; - no. First get a pressure cooker and learn how to use it. They are fantastic but whistling and humidity have little to do with it. To be frank few cooks would have anything to do with this but from a technical point of view you could employ;

  • A temperature guage
  • A strain guage
  • A timer

You need to know if the cooker is made of aluminium or stainless steel.
I would measure the external temperature of the pot, the pressure as determined by the bowing of the pot (via the strain guage), and the time.
This seems quite complex to me, and people are not going to want wires hanging from their pots. However if it could all be integrated into the pressure cooker maybe you have something.

mrburnette; I too am banned! Though I suspect an intent to create a dependency culture. To me at least my spicy Thai chicken soup is a gastronomic wonder.

An external IR temperature sensor might apply.

Who gave you such a task? I bet they don't cook. What is their goal, and what is yours?

You may want to ask for a bigger task. LOL

Jack

jackwp:
Who gave you such a task? I bet they don't cook. What is their goal, and what is yours?
You may want to ask for a bigger task. LOL Jack

Take your meds now! 8)

@zoomkat. You disliked my post. Yes i may need to let off a little steam. Shall I whistle?

I asked 3 important questions. Was assigned this task by his collage teacher, his girl friend, or his boss at work?
What the goals were.

I did throw in a little humor (I thought).

If you have some constructive questions, or suggestions, please post them.

Thanks, Jack

Children - behave.
I think you are hungry and the smells from the kitchen are distracting you :slight_smile:

Everybody on this list minds their place and sticks to technical issues.
The pressure cooker is an interesting, and a surprisingly dangerous part of the modern kitchen lets stick to the technical issues.

Thanks for the posts guys...Well this is a small project given by my college ...just to get to know the difficulty that might be involved in measuring something physical...even though it might sound quite simple :)...I am presently working on an amp for an electret microphone's output...as i thought humidity sensing will just make it more complicated..so will an IR temperature sensor (relatively costly too)...will keep you guys posted..Lemme know if you guys have any more ideas!! :slight_smile:

I don't know how much of the project you're describing is specified for you and how much constitutes part of the solution that you have designed.

If the person specifying this is intending that it does something that could credibly be useful to a cook, I'd suggest that monitoring the temperature would be the most useful thing to do. Zoomcat's idea of using an IR thermometer might be your best bet, although in my experience pressure cookers tend to be shiny metal and that's not a good target for an IR thermometer. So it would be quite hard to do in general, but if you can control the test conditions then it should be possible to get something to work. If you're willing to put something in contact with the lid of the cooker then things get much easier, and you also have the possibility of implementing an over-temperature alarm (aka your pressure cooker has run out of water and is about to be destroyed).