2 Safety instructions (English)
16
2.6. Ambient
conditions
Characteristic
Values
Transmitter ambient
temperature
(electronics)
-20 °C
≤
Ta
≤
70 °C/-4 °F
≤
Ta
≤
158 °F
Protection class
IP 65 (with probe inserted or probe socket
sealed with sealing plug)
2.7.
Connection and zone separation
Connection
Each of the two channels of the testo 6682 transmitter must be
provided with a certified transmitter power supply unit that provides
an intrinsically safe circuit with the protection level ia.
The technical data of the transmitter power supply unit must not
exceed the Ex-relevant data:
• Uo = 28 V
• Io = 93 mA
• Po = 650 mW
For correct operation, the terminal voltage of the transmitter power
supply unit must not fall below 16 V with 20 mA loop current.
