Apogee Instruments ST-110 Manual del usuario - Página 4

Navegue en línea o descargue pdf Manual del usuario para Controlador de temperatura Apogee Instruments ST-110. Apogee Instruments ST-110 18 páginas.

INTRODUCTION

Temperature is generally thought of as the relative degree of 'hotness' or 'coldness' of a specific object or material.

In actuality, temperature is a measure of the average thermal energy (internal kinetic energy) of an object.

Thermal energy is associated with the motion (kinetic energy) of the atoms and molecules making up the

object/material. Higher temperatures correspond to higher thermal energies (faster motion of atoms and

molecules), whereas colder temperatures correspond to lower thermal energies (slower motion of atoms and

molecules).

Properties of materials, and nearly all biological, chemical, and physical processes, are temperature dependent.

Temperature is also a fundamental weather variable. As a result, temperature is perhaps the most widely

measured environmental variable.

Thermometers are sensors that measure temperature. Thermometers are often electronic, with multiple options

available. The main advantages of thermistors over other electronic thermometers (thermocouples, platinum

resistance thermometers) are high signal-to-noise ratio, requirement of only a single-ended channel for

measurement, and low cost, while still maintaining comparable accuracy.

Apogee Instruments ST-100 temperature sensors consist of a precision thermistor enclosed in a waterproof rubber

covering, a precision bridge resistor, and lead wires to connect the sensor to a measurement device. ST-100

sensors are weatherproof and are designed for continuous temperature measurement in air, soil, or water.

ST-110 temperature sensors consist of a precision thermistor, a precision bridge resistor, and lead wires to connect

the sensor to a measurement device. ST-110 sensors are weatherproof, have excellent long-term stability, but do

not offer the same level of ingress protection as the ST-100. The ST-110 is designed for continuous air temperature

measurement when housed in the TS-100 aspirated radiation shield. Thermal conductivity to the precision

thermistor is minimized by using constantan wire, which has twenty-fold lower thermal conductivity than copper

wire.

ST-150 is a platinum resistive thermometer (PRT) enclosed in a stainless steel sheath, and lead wires to connect

the sensor to a measurement device. The sensor is weatherproof and is designed for continuous air temperature

measurement when housed in the TS-100 aspirated radiation shield. The ST-150 is designed to be used with

dataloggers that have resistors built in.

ST-200 temperature sensors have a fine-wire precision thermistor, precision bridge resistor, and lead wires, but

the thermistor is not packaged in a weatherproof housing. ST-200 sensors are weather resistant and are designed

for temperature measurement of delicate surfaces (e.g., leaves, fruits) and small samples (where a narrow field of

view infrared radiometer may not be suitable due to the integration over the conical field of view), or applications

where rapid response is required.

ST-300 is a platinum resistance thermometer (PRT), consisting of a platinum resistive element enclosed in a

stainless steel sheath, and lead wires to connect the sensor to a measurement device. ST-300 sensor are

weatherproof and is designed for continuous air temperature measurement when housed in the TS-100 aspirated

radiation shield.

All Apogee thermistor temperature sensors output an analog voltage (when supplied with an input voltage) that is

related to thermistor resistance. Resistance is directly related to temperature.