Pressure and Thermal Test Chambers, Stress Testing

Needed a way to simulate the repeated heatup and cooldown of the cooking surface and its wireless electronics. So, took an industrial oven (the red circled object), wired into a solid-state relay controlled by an Arduino. Then, added an air-cylinder and valve to automatically open the door, stuck a fan near the door opening. Programmed this all on the Arduino and data logged the results to an SD card. Now, just sit back and wait.

The Arduino would close the oven door, turn on the heater, and ramp up to set-temperature, hold for 20 min and then turn the heater off and open the door to rapidly cool the cooking surface down via the external fan. This would repeat for over 2 weeks.

Testing Outcomes and Changes in the Design

Needed a way to subject the sealed electronics within the cooking surface to conditions seen within an industrial dishwasher. So, took a polycarbonate cylinder, capped it on both ends with an aluminum plate, installed an air fitting on top, connected this up to a 10PSI air source AND a vacuum generator. With the use of solenoid valves, a pressure sensor and an Arduino, the sealed electronics were subjected to pressure variations from +10PSI to -5PSI every 24 seconds for about 2 days

The first rev of the sealed electronics consisted of two plastic sheets sealed with High temp RTV by sandwiching together.

This sealed body failed

For the next version, a machined groove was utilized and the High temp RTV was injected into the groove via a small port; the sealant would flow around the internal groove, sealing the two halves together.

This version produced a more reliable seal over time