HD2717T serie - Interchangeable probe active transmitters The instruments of the HD2717T… series are transmitters, indicators, and ON/OFF regulators with data logging functions, they measure temperature and humidity. The main feature of these instruments is their interchangeable probe. The probe can be replaced by the user without process interruption. Thus, the probe can be calibrated or repaired at a later time. The instrument is available in three different versions: with horizontal probe (S.TO), vertical probe (S.TV) or with remote probe (S.TC), having the probe connected to the electronics by means of a cable of various lengths. The S.TO and S.TV probes are made of stainless steel AISI304, the S.TC probes can be of stainless steel AISI304 or plastic material. For the measurement of dew point in compressed air systems, the S.TC2.480.2 probe can be used.