Topcon DL-501 Instruction Manual page 18

3. PRODUCT OUTLINE
However, even if the DL is used within proximity to the above equipment with no adverse effects
with regard to Bluetooth communication, moving a Bluetooth compatible device (including the DL)
closer to said equipment may result in electronic noise in sound or images, adversely affecting the
performance of televisions and radios.
Precautions regarding transmission
For best results

• The usable range becomes shorter when obstacles block the line of sight, or devices such as PDAs
or computers are used. Wood, glass and plastic will not impede communication but the usable
range becomes shorter. Moreover, wood, glass and plastic containing metal frames, plates, foil and
other heat shielding elements as well as coatings containing metallic powders may adversely affect
Bluetooth communication and concrete, reinforced concrete, and metal will render it impossible.
• Use a vinyl or plastic cover to protect the instrument from rain and moisture. Metallic materials
should not be used.
• The direction of the Bluetooth antenna can have adverse effects upon usable range.
Reduced range due to atmospheric conditions

The radio waves used by the DL may be absorbed or scattered by rain, fog, and moisture from the
human body with the limit of usable range becoming lower as a result. Similarly, usable range may
also shorten when performing communication in wooded areas. Moreover, as wireless devices lose
signal strength when close to the ground, perform communication at as high a position as possible.
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