Cryo test of Sensor Tubing Performance

DESCRIPTION

Sensor tubing will also be susceptible to the extremely cold temperatures.

OBJECTIVE

  1. Determine effect of sustained -60 deg C temperature on flexibility of sensor tubing.
  2. Determine effect of sustained -60 deg C temperature on tubing bending fatigue failure.

EQUIPMENT

  1. outfitted cryo chamber, including
    1. styrofoam dry ice reservoir
    2. mounted fan
    3. temperature sensor
    4. web portal that displays temperature readings
    5. 10 lbs dry ice (if there is not enough left in the styrofoam dry ice chamber to complete the experiment)
  2. dry ice handling gloves
  3. sensor tubing 36” in length
  4. flat table at least 30” in height
  5. clamp that is securely fastened to the flat table

PROCEDURE FOR OBJECTIVE 1

  1. Measure and record the flexibility of the sensor tubing prior to cooling using a modified version of the Calmont Flexibility Test
    1. Hang 15” of the cable off the side of the table (21” on the table)
    2. 6” from the top of the table measure the distance from the table to the cable
    3. 12” from the top of the table measure the distance from the table to the cable
    4. Take the average of the two measurements = “flex value”
  2. Add dry ice into reservoir, if necessary. Be sure to wear the dry ice handling gloves.
  3. Place the same piece of sensor tubing that was measured into the cryo chamber cooled at -60 deg C
  4. Wait 72 hours.
  5. Retrieve sensor tubing from the cryo chamber
  6. Measure and record the flexibility of the sensor tubing immediately by repeating the steps in 1.I-IV.

PROCEDURE FOR OBJECTIVE 2

  1. Measure and record bend fatigue failure of the sensor tubing prior to cooling
    1. Clamp one end of the sensor tubing so that it will remain fixed
    2. Bend the tubing 90 deg in one direction and then 90 deg the other direction
    3. Repeat step 1.II 20 times.
    4. If the tubing fractures before then, record the number of bends it took for the wire to fail; Else, record that the you failed to reach the wire's bend fatigue failure point
  2. Add dry ice into reservoir, if necessary. Be sure to wear the dry ice handling gloves.
  3. Place the same piece of sensor tubing that was measured into the cryo chamber cooled at -60 deg C
  4. Wait 72 hours.
  5. Retrieve sensor tubing from the cryo chamber
  6. Measure and record bend fatigue failure of the sensor tubing immediately by repeating the steps in 1.I-IV.

RESULTS

Starting Dry Ice Weight: 6.23kg

Internal Temperature Log Spreadsheet

  • Lowest Temp Reached: -58.5
  • Fan temp threshold setting: -60

Notes

Time values in this data are inaccurate by a large margin. Do not use, time counting rate is slow. Readings were captured generally at approximately 5 minute intervals.

Results of bending tests

testing/cryogenic/compmat/cryo10.txt · Last modified: 2010/10/28 03:54 (external edit)
 
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