Which of the following instrument is used to measure Soil Water Tension?
A. Photometer
B. Pyrometer
C. Psychrometer
D. Tensiometer
Answer: D. Tensiometer
Solution
Tensiometer
Tensiometer is used to measure Soil Water Tension. A tensiometer is a device used to measure the tension or stress in a material.
Psychrometer
A psychrometer, also known as a hygrometer, is a device used to measure the moisture content of air. The device can also be used to measure the dew point temperature and the wet bulb depression.
Pyrometer
A pyrometer is a device used to measure the temperature of an object or a surface. It works by detecting the thermal radiation emitted by the object and converting it into a temperature measurement. Pyrometers can be classified into two main types: contact and non-contact.
Contact pyrometers, also called thermocouples, require physical contact with the object being measured.
Non-contact pyrometers, also called infrared pyrometers, measure the temperature of an object without making physical contact.
Photometer
A photometer is a device used to measure the intensity or the luminous flux of light. It can be used to measure the light from a wide range of sources, including the sun, stars, artificial light sources, and even fire.
Photometers can be broadly classified into two types: absolute and relative.
Absolute photometers measure the absolute intensity of light, while relative photometers measure the intensity of light relative to a standard source.
Some photometers are designed to measure specific properties of light such as color, spectral power distribution, and luminous efficacy. These are known as colorimeters, spectrophotometers, and luminous flux meters respectively.
