418/433-MHz field-strength meter:

Reliable data transmission using a radio link requires the transmitter signal to be received as clean as possible, and at sufficient fieldstrength. Particularly inside buildings this is often problematic because of reflections and attenuation. The fieldstrength meter presented in this article is specifically designed for type-approved licence-exempt 418/433 MHz shortrange signalling devices (SRDs), allowing the local RF fieldstrength to be measured, and receivers and transmitters to be installed in favourable positions.