Spark Plug Resistance Tester

Tempest AT5K Resistance Tester – fast and reliable spark plug tester

The Tempest AT5K Resistance Tester is designed for aircraft maintenance professionals. This tool makes it easy to check the internal resistance of aviation spark plugs – a common cause of rough-running engines and chronic magneto issues.

How it works:

• Place the spark plug barrel-side down on the contact post
• Touch the firing end of the center electrode with the probe
• Read the LED indication instantly:
  
• Green: resistance < 4 kΩ → good
• Green + Red: 4–5 kΩ → still serviceable
• Red: > 5 kΩ → discard and replace
• 
  

Benefits:

• Quick and clear results
• No complex measuring equipment required
• Prevents engine problems and reduces maintenance costs