Apogee Instruments ST-200 Manuale d'uso - Pagina 8

Sfoglia online o scarica il pdf Manuale d'uso per Regolatore di temperatura Apogee Instruments ST-200. Apogee Instruments ST-200 18.

DEPLOYMENT 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.