HI, all
I am doing project that the arduino board needs to be put in the industrial oven where computer can't be connected all the time. The problem is that how can I store data to be taken out after the experiment without connection with computer.
Please help me out
Thanks
How much data?
For small amounts you can use the internal EEPROM, large(ish) amounts use an external EEPROM, really large amounts use an SD card.
Why does the whole Arduino have to be inside?
Rob
Another possibility is a wifi shield, assuming that the oven enclosure doesn't defeat wireless reception.
How much data?
For small amounts you can use the internal EEPROM, large(ish) amounts use an external EEPROM, really large amounts use an SD card.
Why does the whole Arduino have to be inside?
All data should be 1 MB at least, since there will be 8 channels of thermocouple for 2 hrs.
And the reason why arduino is to be put in an oven because the oven is very very big if I put i outside then thermocouple wires will be very very long.
Any sugguestions?
Another possibility is a wifi shield, assuming that the oven enclosure doesn't defeat wireless reception.
Right now I am finding an insulated box for retaining suitable environment for the board but can't find any so i am not sure if that box will defeat wireless reception.
How hot?
I'm guessing it will be too hot for most circuitry otherwise you wouldn't be using TCs.
Rob
300 degree celcius
But i plan to put it in an insulated enclosure
300 degrees for 2 hours ?
I don't think an inulated box will do for that, unless it is actively cooled somehow.
And what about the wires to the thermo couples?
Here is a copy/paste about allowed wire length to a thermocouple:
What is the maximum length of thermocouple wire?
There are many factors that can impact the usable length of a thermocouple. As a guideline, under 100 feet with 20 AWG or thicker wire in an area free of electromagnetic interference usually is fine. Two of the main factors in determining useable thermocouple length are total loop resistance and preventing electrical noise getting into the signal. Because different thermocouple wires are made of different materials, the resistance will vary based on the type as well as the wire diameter and length. The allowable loop resistance is affected by the input resistance of the amplifier circuit to which it is attached. But as a guideline, typically the objective is to keep the total loop resistance under 100 ohms. Loop resistance is determined by multiplying the length in feet by the resistance per double feet (remember 1 foot length of run includes 1 foot from each of the two t/c wires) as shown in "Resistance Vs Wire Diameter" table for thermocouple type and gauge. Remember in your calculations to include the probe (when used/applicable) in addition to the wire length. The second major factor in running a thermocouple wire is to keep it away from any electromagnetic fields. Thermocouple wire creates a low voltage signal and should not be run near power wires, motors, etc. To help minimize noise pickup, a metal over braid or twisted shielded wire is commonly used.
what if i use a wire with 20meter long 24 AWG, will there be any higher resistance?
thx so much
golfmon:
what if i use a wire with 20meter long 24 AWG, will there be any higher resistance?thx so much
Wire size has a lot to do with the conditions that the wire has to meet. You might be able to use 24 AWG and have no problems even though 20 AWG is recommended. If you must use the smaller wire, you can connect your thermocouples and the metering device and check the calibration using known temperatures. If your thermocouple are giving good readings, you can decide what to do from there.
In industry, Thermocouple simulators are used to test the wiring from the thermocouple to the metering device to insure the conductors are "good". Fluke makes a meter that is used for this testing process. The thermocouples themselves are tested at the factory to insure quality.
Mark`