The ambient temperature of the external NTC sensor. The device has the ability to adjust the set temperature in the range of +5 oC ÷ +60 oC. For proper operation, the device requires the connection of an external NTC-03 probe. The probe is not included with the regulator and must be purchased separately. The probe cable is 3 m long and can be extended up to 50 m with a cable with a cross-section of 0.2 ÷ 2.50 mm2. Probes cannot be combined.