Wireless call buttons have a stated range on the packaging, however this does not necessarily translate to real life situations.
What the Quoted Figure Means
Range figures are generally tested in open spaces. For this reason the advertised figure of say 100m Line of Sight may only translate to perhaps 20-30m in actual usage once walls are introduced.
How Walls and Floors Reduce Signal
Softer walls (stud partitions) lose less signal than solid walls. Each floor in between a wireless call button and its receiver reduces the signal strength even more. A two-story structure with solid masonry walls would lose more than half the signal strength of the quoted wireless range figure.
Other Sources of Interference
Interference from Other Devices that Operate on the Same Frequency Band. So long as other devices that operate on 433 MHz frequency do not also communicate via wireless call buttons (in addition to their other wireless communication), they can cause interference to a call button and thereby reduce its communication range.
For more on this, take a look at www.dinggly.com/products/wireless-call-buttons/.
Mounting Height and Position
The distance that the signal can travel is severely reduced if the call button is mounted to a low level wall or behind a counter. This would mean that the call button would need to be mounted approximately 1 meter above the top of a desk or table and in a straight line to the receiver.
Do a Walk-Test First
The best test for wireless call buttons in your space is to do a walk-test. Tape the button temporarily in place and then do a test walk around the building with the receiver. Note where the signal disappears for good. From this test you can then do the most appropriate fixed layout for your wireless call buttons.
A quick walk-test takes ten minutes and can save a lot of repositioning later.
