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aga
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DAC #4 LabControl Wireless Sensing, Logging and Control
Having thought about this for ages, it's high time Someone made this system :-
A hand held unit displaying and logging all the measurable parameters of any particular reaction, with the the ability to be very simply programmed to
take Action in certain circumstances, such as turn off the heat if temperature X gets above Y for Z seconds etc.
E.g. Simple Distillation.
1. Turn on the heat.
2. Measure/log the vapour temperature every T seconds, or even milliseconds.
3. When temperature hits X for A seconds, move a spout so that the distillate is delivered to the collection vessel.
4. When vapour temperature hits Y for B seconds return the spout to the waste collection vessel, and turn off the heat.
5. Beep a lot to tell me it's finished.
To achieve this, and at a very low cost, cheap microcontrollers and €1 radio transceivers can be used.
For the Sensors/Controllers the nRF24L01 is ideal, as are any of the PIC series (€1 16F1823 leaps to mind).
An Arduino with a touch screen LCD shield is of such low cost and such high processing power, it would be mad not to make use of it as the Hand Held
control unit.
The sub-tasks are :-
1. Design a radio protocol to transfer data to/from the devices to the controller.
2a. Design the Sensor Analogue amplifier(s)
2b. Design/write the microcontroller code adhering to the protocol in (1)
3a. Design/write the Arduino LCD User Interface and control language.
3b. Design/write the Arduino nRF24L01 interface board and interface.
A chunk of this is already half-done, and i could just do it all myself, buy am clearly not getting on with the job due to other pressures on my time.
Sensor Modules required :-
1. Thermometer (thermocouple). This obviously needs at least a 2-point Calibration procedure.
2. Pressure Sensor
3. Vacuum sensor
Controller Modules required :-
1. 110/230VAC PWM controller capable of 5KW peak.
2. 4 to 12v PWM controller capable of 60W peak (for electrolysis)
3. Three position servo, so we can move stuff about as-and-when
With that lot all wirelessly connected, there is plenty that can be made easier, and would help log all the data from experiments.
There is plenty of scope for expanding the types of sensors and controllers.
Where should the Money reward be in this DAC ?
I'm not sure : Suggestions please.
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Oscilllator
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Hmmm, I've just gotten into arduino myself and am currently waiting for shipment of a thermocouple. Methinks this might be just the challenge I'm
looking for. I even have a PWM controller, although I don't know its peak power output. It is capable of heating a 1L mantle to hotter than it should
be, though.
I think the money reward should go to the person who gets the most sensors/controllers working properly. One more idea for a controller could be
magnetic stirrer RPM.
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Zombie
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A dear friend of mine has beat you to the punch here.
Istill 250. http://www.istill.eu/#!istill-products/c17ty
It's is a completely automated still. Does everything except rub your back.
His next generations will include automated grain, and bottle ordering, Self cleaning cycles, and complete accounting for every drop produced.
The only difficult part here is finding servos, and valves that "Play Well" together.
All the software is written, and the parts available from him.
For an extra 50.00 bucks, I'm sure a back rub can be had.
Odins, kind of a pimp!  (just in case) Love Ya Odin!!!
[Edited on 3-3-2015 by Zombie]
They tried to have me "put to sleep" so I came back to return the favor.
Zom.
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Bright Spark
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Hey aga
Theres no doubt its a big project and I need to learn the simple still stuff so I will look at this,
What temperature range do we need to measure in stills?, I have seen some thermistors that go upto 300C and this makes the most simple electronics
going and using the manufacturers data you can get very accurate results without ever needing to calibrate, anyway thats a story for another day
Whats the temp range we measure?
Are the pressure sensors in different flasks?, I have seen differential pressure sensors used to measure vacuum, one side measure atmosphere, so its
possible to measure DP and knowing atmospheric pressure allows us to know lots with one sensor however my lack of knowledge means I don't know where
we need to measure stuff hence I might be talking crap
Getting a 5kW output is a problem, the UK standard plugtop can deliver 3kW, so over this and you need a dedicated supply which makes the product
inconvenient
Oscillator, get a cheap thermistor to start, one that measures 10k@25C, also get a 10k resistor and setup a divider, this will allow you to learn fast
Zombie
The setups look awesome
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j_sum1
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Bright Spark. I am glad you are looking at this. It sounds like just the sort of thing that will get you familiar with the things you want to know
and will employ a lot of your specialist skills. let me encourage you to give it a shot.
I am out for this one. I lack the electronic know-how and equipment.
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aga
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Perhaps delegating a Sensor to someone, and if they come up with a working design, they get some $ ?
Just thought : a Weight sensor would be useful too, as would a liquid level sensor.
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aga
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AutoShine !
Looks great.
What i;m after is more a general set of sensors and controllers that could be applied to many different types of reaction, not just distillation.
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Zombie
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A few thoughts off the top of my head...
It's not so much the specific temps. that are important but rather the changes in temps.
Lets say acetone comes off first, and the vapor temp is 160*f
The boiling point or temp in the boiler is set by the composition so you have no control there. But as the acetone boils off the temp. in the boiler
goes up.
Then your next compounds begin to vaporize. Lets say 165*f.
At each of these first two stages you have to hold the temp steady to stabilize, and completely remove these products. Therefore a timer circuit is
required.
Comparing time to boiler temp is the only way to separate fractions from the boiler. You can do this without a comparator (time) but complete
separation is not guaranteed or even known.
After the most volatile components are removed are the boiler will run at somewhat consistent temps but again as the EtOH is evaporated the temp will
steadily increase. This is predictable based on mole fractions, and it will be independent to every run depending on the beginning product.
Mr. Aga,
You might want to narrow this down a little, and specify a beginning "wash" for the boiler ie: Jack Daniels Whiskey or Gallo Rose wine, home made
sugar / yeast wash at 10 - 15% abv, ect...
Is the intent to make a palatable EtOH (moonshine), Fuel grade EtOH? Azeotrope? Dry EtOH?
Specific ABV?
Without a column distillation the average ABV will be approx 40% if you start with a 10% abv wash.
A water cooled or reflux column will reach azeotrope but again temps will depend on the boiler content.
Volumes can be calculated but I think fluid level in the container is much more important for an automated container exchange.
It can all be done via Arduiono, and PID's. You could even start with the software used to climate control your house... Just change the numbers.
While I won't be building in this, I will be happy to assist with brainstorming. I know all the mechanics involved.
They tried to have me "put to sleep" so I came back to return the favor.
Zom.
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Sulaiman
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Aga,
I think that the challenge is un-necessarily complex.
using wireless connections (other than possibly remote access to the main controller) adds so much work for no practical gain.
Even large scale industrial processes use wire or fibre for reliability
(I know of exceptions but do we need them?)
and small scale systems such as members here would use, would end up with MORE wiring due to power requirements.
If collaborative development is envisioned then data and communications protocols would have to be standardised.
I see three main scenarios;
a one-off specific task home built lash-up which would not really help others other than with general ideas.
or
small scale use of commonly available (e.g. arduino) modules
with minimal electronics knowledge required to set up.
The main effort would be
. developing shareable code
. developing reproducible application specific sensors, actuators etc
or
Industrial scale using P.L.C. etc.
a sober re-think may be in order?
[Edited on 4-3-2015 by Sulaiman]
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aga
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I envisaged Power to come from 3v Li button cells, with about a 2 to 3 year life, eliminating all wires.
It doesn't seem complex to me at all, and breaks down neatly into sub-units, making the overall task much easier.
Probably it won't work as a 'Challenge' in this way.
Perhaps i'm not properly describing the system as i imagine it.
Maybe if it get it started by building the hand held display and one Sensor unit (thermometer) then others could jump in and make other sensor units.
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Sulaiman
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Will you trust your automated experiment to potentially worn out batteries?
and
heaters, stirrers, valves, pumps .... will need more than a little battery to operate.
sorry if over-critical but my job is repairing industrial automation of all types and brands
and I am familiar with a near infinite number of failure modes.
P.S. given the overall cost of sensors and actuators and the now reasonable cost of integrated P.L.C.s,
which incorporate human interface, easy programming, safety, quick and easy replacement,
thermocouple/PTC/analogue/digital.... inputs
analogue/digital/relay/triac/motor... outputs
the DIY approach is questionable.
(consider how much you will spend on casing, power supply, connectors, display, interfaces etc.,
the work of putting it all into the case, the finished size and appearance, safety considerations .....)
(as an electronics hobbyist I hate this, there are very few things that can be made cheaper/better than ready made,
as a hobby it's fine, but if chemistry is your main hobby then this will be a struggle)
[Edited on 4-3-2015 by Sulaiman]
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Bright Spark
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I agree the wireless part adds extra complexity, a better system IMO is to have the unit do what it does and have wireless to simply send data which
can be logged to a PC serial port, and a PC can be used to display whats happening
The wireless part would be added later anyway, I have been looking around but its hard going, I have asked a few times what temp range but I am no
further forward
Using standard parts is good but I think this project needs its own PCB otherwise it will all be messy, I think I will try and build the temperature
controller first, I need a heater maybe I can use anything to get the system going but ideally I need a magnetic stirrer hotplate which I can hack
Tell me guys what should I buy when it comes to stirrers/hotplates
I have some sensors at work and a few ideas
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Sulaiman
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do you really want to diy when you can buy an auto-tune PID temperature controller with probe for GBP10 to USD20 ?
E.G http://www.ebay.co.uk/itm/PID-F-C-Digital-Temperature-Contro...
from similar vendors you can choose
sensor: Thermistor, Thermocouple (typically J or K), RTD etc.
output; transistor, relay, ssr etc.
These things are so small that you can build them into the front panel of a cheap hotplate.
I bought a J- and a K-type stainless steel clad thermocouple (for different equipment) and they seem ok.
[Edited on 4-3-2015 by Sulaiman]
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mayko
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personally, I'm opposed to sensor-ship.
(I'm sorry. I'm so, so sorry.)
al-khemie is not a terrorist organization
"Chemicals, chemicals... I need chemicals!" - George Hayduke
"Wubbalubba dub-dub!" - Rick Sanchez
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aga
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LOL.
Temperature range would depend on whichever thermistor, or preferrably a thermcocouple you wish to use.
I like the Negatives. Spurrs me on to simply get on and Do this thing and show you what i mean.
No, it doesn't already exist already cheaper or better.
Yes, you can buy a PID controller for whatever power source you have,
Yes, you can buy a digital thermometer.
Yes you can buy a PLC.
Hell, yes you can buy a Computer.
Yes to each SEPARATE COMPONENT OF AN INTEGRATED SYSTEM.
What i'd like is the equivalent of Quickfit for the sensors, data logging and automatic Control of my experiments, no matter what those experiments
may be.
This does Not already exist at all, as far as i know.
The thermometer sensor will be a blob on top of a thermocouple with at least 2 year's battery life.
No wires, just a blob on top of a metal stick that i can put in my stillhead, beaker, furnace flame etc etc that effortlessly enables the recording of
that temperature in the hand held unit, eventually for download onto my pc.
Chemistry is New to me. Electronics and programming various devices are not.
Edit:
Sorry for shouting.
DAC #4 is Suspended until aga gets his arse in gear and builds the entire thing so photos can be shown instead of mere words, as relying on
Imagination being available failed dismally.
[Edited on 4-3-2015 by aga]
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Sulaiman
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sorry, I missed the shout, I'm deaf in one eye.
I didn't realise that you were electronics oriented, I wrongly assumed mainly chemistry.
found this
http://www.ebay.co.uk/itm/RF-WIRELESS-RADIO-THERMOMETER-AND-...
I realise it is not what you want but it does show that there are others who have similar needs and could serve as a housing for a pre-miniaturised
prototype.
I also found "iGrill" for iphone
http://www.ebay.co.uk/itm/iGrill-Wireless-Cooking-Thermomete...
even bulkier.
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aga
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You can Find many things all over the internet.
Cost and lack of Integration is forever the problem.
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Bright Spark
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| Quote: |
Temperature range would depend on whichever thermistor, or preferrably a thermcocouple you wish to use. |
Well yeah, thats the obvious part I am asking what temperature range do you need?>
Whats the temperature range that a still rig needs to achieve?
If i made a system that could only measure up to 100C that wouldn't be any good so tell me, whzt temps do you want to measure right now this is the
million dollar question
| Quote: |
Relying on Imagination being available failed dismally |
I have imagination, but I am not a mind reader, you haven't specified this project no where near enough for someone to start theres too much missing
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aga
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-50 to +200 C would be more than adequate for almost all of my experiments.
http://www.ebay.co.uk/itm/K-Type-thermocouple-temperature-se...
For the high temperature stuff, 1300 C would be the most i'd even hope to achieve.
http://www.ebay.co.uk/itm/3m-High-Temperature-100-1250-Degre...
It'd be the same analogue circuit for each, with the calibration done in the firmware, so the same code for each thermocouple.
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Zombie
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Rain Water Level Sensor module Depth of Detection Liquid Surface Height Arduino
Useful Tank Liquid Water Best Sale Level Sensor Float Switch Stainless Steel
Two liquid level options from Ebay.
The Arduino is three bucks shipped, and the float is eight
 
They tried to have me "put to sleep" so I came back to return the favor.
Zom.
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aga
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The float sensor would be useful, and an easy project for someone.
(if the RF comms code were already done).
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Oscilllator
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I already have the water sensor, so perhaps I could start with that. I don't know how well it would work for non-polar solvents, though.
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Zombie
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I came across this today...
A digital temp. probe, and the software to run it via Laptop / smart phone / email...
Maybe there is something in it for your application.
http://www.vernier.com/products/sensors/temperature-sensors/...
https://github.com/toofastcomet/TempMaster/wiki
[Edited on 3-14-2015 by Zombie]
They tried to have me "put to sleep" so I came back to return the favor.
Zom.
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Bright Spark
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I am still around guys, I have had a lot on lately work uni home it all clashes
I am still educating myself, I have an organic chemistry book and the Organic Chemists survival guide by Zubrick
I have bidded on an IKA stirrer/hotplate so its looking good I will get the equipment and what not bits at a time
Glassware seems like a complicated area! so many different names and weird and wonderful shapes
A digital temp. probe, and the software to run it via Laptop / smart phone / email...
Looks good but $50 isn't cheap but its not mega bucks either
I like the look of these
http://datasheets.maximintegrated.com/en/ds/MAX31855.pdf
Cold junction compensation built in with an SPI output so its trivial to program
I have some hardware, I have stacks of code to drive things like LCD's, thermistors etc but in the coming weeks I will make a new PCB
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Zombie
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Now that converter is just cool!
Ebay has these EGT sets (exhaust gas temp) used on 2 stroke bikes for 20 bucks, and free shipping.
I imagine it a simple conversion of the gauge to be used as the interface. You could then avoid the price of the converter box.
http://www.ebay.com/itm/Digital-DC-Temperature-Meter-for-K-T...
I actually have two of the gauges (minus thermocouple) if you want one to mess around with.
U2U me if you are interested.
They tried to have me "put to sleep" so I came back to return the favor.
Zom.
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