STC Smartscan NG2, Manual

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EUD-2018086-00 Rev.3, SmartScanNG² User's Guide for Wayside Enclosure Components, 14 May 2021
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5.0 Shielded Temperature Probe
The temperature probe is encased in a radiation shield that shields it from direct sunlight and
allows ambient air to flow through and around it. The probe mounts to the outside wall of the
wayside enclosure and provides accurate temperature indications over a range of -45°C to
+65°C (-49°F to +149°F). Site ambient temperature (when the train passed the site) is
included with most system reports. There is one shielded temperature probe per system.
The figure below shows the major parts of a shielded temperature probe (2090-100).
The SmartScanNG² system supplies 12 volts to the shielded temperature probe. The probe
returns 0 to 5 volts. Zero volts indicate a -45°C (-49°F) reading. Five volts indicates a +65°C
(+149°F) reading. During normal operation, you should probably never get either reading.
Therefore, if you get a -45°C (-49°F) reading, the probe could be malfunctioning, the cable
from the probe to the SmartScanNG² detector could be cut, or the wiring to the
System-Interconnect board could be disconnected. If you get a +65°C (+149°F) reading, the
probe could be malfunctioning, or the ground wire from the probe to the SmartScanNG²
detector could be cut.
The system comes with a partially installed shielded temperature probe. Section 9.8.5 -
Shielded Temperature Probe tells how to finish installing it.