Mine Foreman Exam Instruments And Apparatus (Anemometer)

An anemometer determines air velocities by measuring the lineal feet of air travel, which is then recorded on the dials. This means that the anemometer calculates the distance the air has traveled in a linear path and displays this information on its dials. This allows for the determination of air velocity based on the measured distance traveled by the air.

An anemometer is used to measure the velocity of air currents. In mines, it is held in an air current for a specific duration to determine the lineal feet of air passing each minute. By measuring the distance the air travels within a set time frame, the anemometer can calculate the velocity of the air current. This information is crucial for assessing ventilation and air quality in mines.

Prior to taking an air velocity reading, it is necessary to set all dials to zero. This ensures that there is no initial reading or measurement on the dials that could affect the accuracy of the air velocity reading. By setting all dials to zero, any previous measurements or readings are reset, allowing for a fresh and accurate reading to be taken.

Air velocities are typically measured over a period of one minute. This duration allows for a sufficient amount of time to accurately capture and average the velocity of the air. It provides a representative measurement of the air movement within a given space or environment.

An anemometer is an instrument that measures lineal feet in air travel and resembles a disk fan. This means that it can measure the distance traveled by air as well as have a physical appearance similar to a fan with a disk shape.

CFM stands for Cubic Feet per Minute. It is a unit of measurement used to quantify the volume of airflow in a given time. This measurement is commonly used in various industries, such as HVAC (Heating, Ventilation, and Air Conditioning) systems, to determine the efficiency and capacity of air circulation.

The cross-sectional area of an entry is determined by multiplying the entry height by the entry width. This is because the cross-sectional area of an object is calculated by multiplying the dimensions that define the shape of the object. In this case, the entry height and entry width are the dimensions that determine the shape of the entry, and multiplying them together gives the cross-sectional area.

The cross-sectional area of a shape is calculated by multiplying its height by its width. In this case, the entry is 4 feet high and 10 feet wide. Therefore, the cross-sectional area is 4 feet multiplied by 10 feet, which equals 40 square feet.

The correct answer is Both C&D. The formula given in option C (highXwideXreading=CFM) is incorrect as it does not accurately calculate the quantity of air moving through the airway. Therefore, option C is incorrect. Option D (30,000) is also incorrect as it is not a valid calculation based on the given information. Thus, the correct explanation is that neither option C nor option D provides the correct quantity of air moving through the airway.

The cross-sectional area of a rectangular entry can be calculated by multiplying its height by its width. In this case, the entry is 6 1/2 feet high and 20 feet wide. To find the cross-sectional area, we convert the height to a decimal by adding 1/2 to 6, resulting in 6.5 feet. Then, we multiply 6.5 by 20, which equals 130 square feet.