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R302-A Materials Testing Oven


Our testing/Curing Oven

The R302-A Materials Testing oven was originally designed for strain testing of materials at widely varying temperatures. It originally covered the range -20ºC - 100ºC and included a cooling system as well as a heater. We have re-purposed it, disabling the cooling system and increasing the top temperature range so that it now covers from ambient up to 250ºC. Owing to the precision temperature controller that it's fitted with it can hold a temperature to within approximately +/- 0.2ºC The oven is in the south-west corner of the main workshop, next to the heat pump

Current Status[edit]

Date Status Comment
13th June 2019 Fully functional One bulb blown but the oven still works

The R302-A Oven was donated by Dean Forbes, and he must be consulted before the oven is disposed of if we decide it's no longer required. The oven was originally used at NPL for testing materials under strain at varying temperatures, so it has openings on the top, bottom and side which can be used to introduce or remove materials while the oven is hot. The cooling system on the oven has lost gas over the years and no longer functions, we've decided against re-gassing it as if we do that then we will not be able to use the oven at temperatures over 100ºC, we feel that being able to get to +250ºC is more valuable than being able to get to -20ºC. There is a powerful circulation fan in the oven that is used to maintain an even temperature throughout the volume of the oven and for that reason special care must be taken when heating anything with powders or loose parts. It can be used for a variety of jobs including softening plastics, curing glues and resins, and tempering freshly hardened metals. It may also be possible to use the oven to bake out investment-casting molds as there is a drain port in the bottom of the oven to let wax escape. The manual for the controller is available here but please be very cautious about making any changes to the internal settings of the controller as it's possible to cause damage to the oven or render it non-functional.

How to use[edit]

The Oven controller

This is the procedure to set a temperature and operate the oven, please note that the cooling system is non-function so do not depress the "COOL" button as it won't work and will inhibit the heater.

  1. Check the oven is empty and that your intended job will fit
  2. If you job is likely to leak liquids or otherwise leave a mess the line the bottom of the oven in metal foil and use a tray.
  3. Place your job into the oven if it is to be heated up from cold, if it's to go in hot then wait
  4. Turn the oven on with the main power switch
  5. Turn the light on with the "LIGHT" button
  6. Press the "RESET" button
  7. Press and hold the "I" button on the controller
  8. Use the up (IIII) and down (IIIII) arrows to set your target temperature
  9. The large number at the top is the current temperature, the smaller number labeled "SP" is the target temperature
  10. Release the "I" button
  11. Press the "HEAT" button which should light up, indicating the oven has begun to heat, if the temperature set is quite low then it may take several seconds for the light to come on
  12. Wait for the oven to come up to temperature
  13. Add your materials if they were to be be added hot
  14. Do whatever processing you wanted to
  15. To turn the oven off press the "HEAT" button so that it pops out
  16. Wait for the oven to cool, it should not be left unattended while hot
  17. Turn off the light
  18. Turn off the main power switch
  19. Clean out the oven

Planned Upgrades[edit]

Parts and upgrades that are planned/Budgeted/Purchased for in the near future

  • New blanking plugs for all the openings

Oven Caretakers[edit]

These are the people who look after and repair the oven, they're the ones to contact if there's any problems with it

Name Notes

Recent Changes[edit]

If you make any non-trivial changes to oven or perform maintenance please note it here, delete records older than 1 yr

  • New circulation fan and motor fitted
  • New fan-guard made and fitted Stever (talk) 09:48, 14 June 2019 (UTC)
  • Deep-clean Oven, re-calibrate thermostat, re-learn PID parameters. Stever (talk) 16:54, 15 April 2020 (UTC)