What are some specific safety indications for using the compression tester device?

The maximum pressure should not be exceeded to avoid serious injury or material damage.
The compression tester should only be used in well-ventilated areas due to toxic exhaust gases.
All safety measures and instructions in the engine manual must be followed before using the compression tester device.
When warming up the engine for testing, the vehicle's gear should be in neutral or 'P' position and the handbrake should be engaged.
Hands and fingers should be kept away from the engine's moving and hot parts.