Typical influences on the signal quality
| Steel cover | up to -30 dB |
| Concrete cover | approx. -10 dB |
| Environmental influences | up to -15 dB |
| Installation height of the antenna | approx. -5 dB / 15 cm depth |
| Vertical/horizontal alignment | approx. -10 dB |
| Horizontal alignment | up to -15 dB |
| Centre/edge of the shaft | approx. -10 dB |
| Other influences | Transmission power of the network operator |
Tip: Practical example:
| Mobile signal level | Position | |
|---|---|---|
 | -67 dBm | Reference measurement outside the shaft |
 | -103 dBm | Measurement at a depth of 1.20 m |
| -95 dBm | Vertically on the edge of the shaft at a depth of approx. 15 cm |
 | -83 dBm | Centre of the shaft, horizontal on the steel fitting |
 | -89 dBm | Antenna turned by 90° |
| -78 dBm | Centre of the shaft, vertical |
| -75 dBm | Plastic pipe used instead of steel fitting |
