Apogee Instruments ST-300 Owner's Manual - Page 8
Browse online or download pdf Owner's Manual for Temperature Controller Apogee Instruments ST-300. Apogee Instruments ST-300 18 pages.
Print PageDEPLOYMENT AND INSTALLATION
Apogee ST Series temperature sensors are designed to be mounted inside solar radiation shields, such as the
model TS-100 fan aspirated radiation shield (see picture below). ST-100, ST-150, and ST-300 sensors can also be
buried in soil/porous media, or submerged in water. ST-200 sensors have thin, flexible wires near the fine-wire
thermistor and are less sensitive to breakage than similarly-sized fine-wire thermocouples.
The temperature measurement returned by a temperature sensor is the temperature for the sensor itself and not
that of the environment the sensor is in, unless the sensor is in thermal equilibrium with the environment. In order
to get representative temperature measurements, ST series sensors must be in thermal contact with the medium
of interest. Accurate air temperature measurement requires a radiation shield (see picture below) to minimize the
effects of shortwave radiation absorption (causes warming; occurs during the day) and longwave radiation
emission (causes cooling; occurs on clear nights) by the sensor. Proper ventilation is also required to ensure
coupling and thermal equilibrium with air. Condensation on air temperature sensors can pose a problem because it
is a source of latent heat that can warm the sensor. When the condensed water evaporates, it cools the sensor via
removal of latent heat (evaporational cooling).
During installation of ST-100, ST-150, and ST-300 sensors in soil, care should be taken to minimize soil disturbance,
which may potentially alter soil thermal properties.
Top left: SP-230 Heated Pyranometer
Center: TS-100 Fan Aspirated Radiation Shield
Right: RM Young 41303 Static Solar Radiation Shield.