What is the use of wet bulb and dry bulb thermometer?
An instrument used to measure the amount of water vapor or relative humidity in the air. It is a combination of wet- and dry-bulb thermometers mounted on a frame with a handle that allows it to be swung around to permit air to move across the psychrometer. See psychrometer.
What is the meaning of wet bulb temperature?
The Wet Bulb temperature is the temperature of adiabatic saturation. This is the temperature indicated by a moistened thermometer bulb exposed to the air flow. Wet Bulb temperature can be measured by using a thermometer with the bulb wrapped in wet muslin.
How does a bulb thermometer work?
Bulb thermometers follow the simple principle that liquids change their volumes relative to their temperature. As temperatures rise, the mercury-filled bulb expands into the capillary tube. Its rate of expansion is calibrated on the glass scale.
How accurate is a bulb thermometer?
Wet- and dry-bulb temperature measurement is a commonly used and widely accepted technique for controlling relative humidity in environmental chambers. According to this standard, the accuracy which can generally be expected in the case of a ventilated dry- and wet-bulb device is in the range of 2 to 5 %RH.
Is filled in the bulb of a thermometer?
Mercury metal is used in the bulb of thermometer. This is because of its high boiling temperature and its high coefficient expansion.
Why the bulb of thermometer is small?
A smaller bulb contains less mercury and hence absorbs heat in shorter time. As a result it can response faster to temperature change. A glass bulb with thinner wall can transfer heat to the bulb easier. Therefore, the thermometer can response quickly to small changes of temperature near the surrounding.
Does smaller bulb increase sensitivity?
As sensitivity generally refers to the change in physical quantity (i.e. length of liquid column) per unit change in temperature, a greater bulb increases the sensitivity of a liquid in a glass thermometer.
Where should the bulb of the thermometer be and why?
The bulb part of the thermometer is positioned near the side arm of the Y-adaptor so that it monitors the temperature of the vapors. If it is too low, it will be too close to the boiling liquid and will read higher than the true vapor temperature.