This is a collective page to informally document what we learn from preliminary research informally.
General guidelines:
What type of device (more specific than just “thermocouple”)?
What grade of device (on a range from hobby/DIY - industrial grade)
How do we use the device (power, signal connections, press a button, etc.)
How/where do we mount the device (epoxy, thermal tape, paste, frame, etc.)
What can go wrong with mounting and ways around it
EX: routing thermocouples in nose cone requires for wire to run into the airframe to reach the DAQ system, jeopardizing deployment of the nose cone
Potential solutions: use special wires that break during deployment, embed copper contacts into the airframe/nose cone shoulder
Based on the info collected above, what are the common price ranges?
Can you list some potential sensor candidates or suppliers? If so, please do.
Remember to label where you found certain sections of your highlights.
Assignments:
Thermal - Eric & Juan
Vibration - Yasu
...
Flutter - Yasu
Thermal (Eric + Juan)
Omega's 5 Points:
HOW TO CHOOSE A THERMOCOUPLE
1. Determine the application where the thermocouple will be used
2. Analyze the temperature ranges the thermocouple will be exposed to
- Max 800 K (980 F) --> Type J, E suit this max (J: 32 - 1400 F, E: -328 - 1600)
3. Consider any chemical resistance needed for the thermocouple or sheath material
4. Evaluate the need of abrasion and vibration resistance
5. List any installation requirements
- Coltronic 4700 thermal epoxy
Sheath Considerations (for sheated thermocouples)
- Grounded vs Ungrounded --> We want grounded (probe wires are physically attached to the wall of the sheath) to maximize thermal contact, no concern for electrical isolation
Other Notes:
https://www.epj-conferences.org/articles/epjconf/pdf/2017/12/epjconf_efm2017_02075.pdf
Calibration is key
Temperature Calibration Uncertainty detailed in Guide to exp. Of Uncertainty in Measurement
“Intrinsic Thermocouples” might give us better spatial resolution (microtips)
https://www.epj-conferences.org/articles/epjconf/pdf/2017/12/epjconf_efm2017_02075.pdf
Seebeck effect
G,C,D are for high temp, K for VERY high temp
NiCr-NiAl used in experiment is oxidation proof, resistant to higher temps, reducing atmosphere, and sulphur compounds
“The thermocouple-based method has some limitations. One of the major problems is attaching a thermocouple to the surface to be measured. Incorrect bonding may cause the device to show a temperature lower than the actual one. When a thermocouple is used to measure the temperature of an element in a high frequency radio circuit, it may change the electrical characteristics of that circuit. A thermocouple fixed to a small electronic element may be responsible for the removal of heat from the element. As a result, the temperature displayed is lower than the actual temperature, i.e. one measured before the thermocouple was attached. Decalibration may lead to an error in measurement; it may change the electrical characteristics, which will make the reading inaccurate. Finally, an open thermocouple junction may also cause errors in temperature measurement [19].
...
"
Possibly add IR Thermal camera for data fusion
Vibration (Yasu)
ceramic piezoelectric sensor/ accelerometer
single axis / triaxial accelerometer
Engineer’s guide to accurate sensor measurements: http://download.ni.com/evaluation/daq/25188_Sensor_WhitePaper_IA.pdf
what’s the effect of the constant acceleration/deceleration of the rocket on the sensors?
triaxial, +-500g, 2~7000Hz model(356B21): $1,125
...