Failsafe

The orange flames licked the edges of the quilt. They crawled back across the floor. They inched up the walls like so many hungry butterflies. The light flashed on the smoke detector in the ceiling, but it didn't beep. The high temperature cameras in the ceiling captured the bright progress, showing the testers on screens in the observation room.

Janet checked the temperature feed from next to the smoke detector. 207⁰. If the smoke didn't set it off, the temperature should have by now. She looked back out the observation window in time to see the simulated bedroom's window shatter.

She sighed and ticked a box on her clipboard. She pressed a button that sounded an alarm for the fire crew to put out the blaze. Janet turned to her crew. "Ideas, what failed?" she asked.

"Not enough smoke to trigger the sensor," suggested Drake.

"Were you watching that video feed? That room was full of smoke!" Phil glared at Drake. "The sensor probably wasn't lit to start with."

Janet rubbed her forehead, "You're probably right, that's most logical right now. What about the heat sensor?"

"Rusted lead?" suggested Phil. "It wouldn't conduct even when the casing melted."

Drake glanced at Phil. "The casing could have melted onto the contact, preventing conduction."

Janet nodded again, both plausible. She looked back at the screens to see the firefighters unhooking the smoke detector from the smouldering ceiling. "Let's take a look and find out what caused fatal failure."

They pulled the half-melted prototype apart on the lab table. Phil took the photoelectric sensor and ran a current through it. "It's not lighting," he said, "The circuit's broken somewhere."

Drake examined the heat sensor. "The lead is rusted," he said. "It wouldn't conduct well, if at all. The casing melted all over the contact too, though."

Janet slammed her forehead on the table and slumped back in her chair. Three years of designing, prototypes and testing and they still couldn't get both sensors to work reliably. The funders will not be happy.