Effective Study Notes Overview

Parts per million (ppm) is a unit of concentration used to express the amount of a substance present in a mixture or solution. It represents the number of parts of the substance per one million parts of the mixture.

Milligrams per cubic meter (mg/m³) is a unit of concentration used to express the amount of a substance present in the air. It represents the mass of the substance in milligrams per cubic meter of air.

The Time Weighted Average (TWA) represents the average concentration of a substance a worker is exposed to over a specific period of time. It considers both the concentration of the substance and the duration of exposure.

The Threshold Limit Value (TLV) is a guideline set by organizations like OSHA and ACGIH to indicate the maximum concentration of a substance that a worker can be exposed to over a specific period of time without experiencing adverse health effects.

TLV-TWA represents the Threshold Limit Value for a time-weighted average exposure. It is the average concentration of a substance a worker can be exposed to over an 8-hour workday without experiencing adverse health effects.

The Lower Flammable Limit (LFL) represents the lowest concentration of a flammable substance in air, below which it will not ignite or explode.

TLV-STEL represents the Threshold Limit Value for a Short-Term Exposure Limit. It is the maximum concentration of a substance a worker can be exposed to for up to 15 minutes without experiencing adverse health effects.

The Combined Gas Law combines Boyle's Law and Charles's Law to describe the relationship between pressure, volume, and temperature of a gas.

Boyle's Law states that the volume of a gas is inversely proportional to its pressure at constant temperature.

Charles's Law states that the volume of a gas is directly proportional to its absolute temperature at constant pressure.

The formula for calculating electrical power is P = VI, where P represents power, V represents voltage, and I represents current.

Ohm's Law describes the relationship between voltage, current, and resistance in a circuit.

In a series circuit, the total resistance is the sum of individual resistances. This means that adding more resistors in series increases the total resistance.

In a parallel circuit, the reciprocal of the total resistance is equal to the sum of the reciprocals of individual resistances. This means that adding more resistors in parallel decreases the total resistance.

The formula N = N0e^(-kt) describes radioactive decay, where N is the remaining radioactivity, N0 is the original radioactivity, t is time, k is the disintegration constant, and e is the base of the natural logarithm.

The formula S = 6CiEf describes the shielding required for radiation, where S is the required shielding, C is the radiation's energy, i is the radiation intensity, E is the radiation efficiency, and f is a scaling factor.

The ratio of the weight of a load lifted to the recommended weight limit (RWL). It helps determine physical stress in lifting tasks.

The maximum weight that a person can lift safely and repeatedly without experiencing undue physical strain.

A tool used to calculate the RWL based on variables like the weight of the load, its distance from the body, and the worker's posture.

A function that allows you to calculate the mean, standard deviation, and correlation between data points.

A function that lets you change the sign of numbers from positive to negative or vice versa. Useful for mathematical operations.

The speed at which air moves through a duct, measured in feet per minute (fpm).

The force exerted by the moving air in a duct, measured in inches of water gauge (``wg).

The pressure exerted by the stationary air in a duct, measured in inches of water gauge (``wg).

Total pressure in a duct, measured in inches of water gauge (``wg). It's the sum of static pressure and velocity pressure.

The amount of air moving through a duct per unit of time, measured in cubic feet per minute (cfm).

The rate at which a substance evaporates, measured in pints per minute.

A safety factor that accounts for potential variations and uncertainties in dilution ventilation calculations.

The concentration of a substance in air, measured in parts per million (ppm).

The acceptable concentration of a substance in air, measured in parts per million (ppm). It's the maximum safe exposure level.

The rate at which a gas or vapor is released into the air, measured in cubic feet per minute (cfm).

The amount of sound energy passing through a unit area per unit time (W/m²).

A logarithmic scale that measures the intensity of sound relative to a reference level.

A logarithmic unit used to express the ratio of two sound intensities.

Doubling the distance from a sound source reduces the sound intensity by half, which corresponds to a 3 dB decrease in SPL.

Calculating the total SPL of multiple sound sources, where each source contributes individually to the overall sound level.

The average sound level a worker is exposed to over a specific period, usually an 8-hour workday.

Calculating the total sound pressure level generated by N sources, accounting for their individual levels.

The sound level of an individual noise source, contributing to the overall sound pressure level.

The ratio of the calculated exposure time (C) to the authorized exposure time (T) for a noise source.

The force required to overcome static friction between two surfaces in contact.