Physical Measurement Specialist Air Laboratory Study Guide

Vocabulary practice flashcards covering air laboratory instrumentation, physical measurements, calibration, particulate matter, gas monitoring, radiological assessment, and quality assurance principles.

Accuracy

The closeness of agreement between a measured quantity value and a true quantity value; it increases as systematic error decreases.

Precision

The closeness of agreement among repeated measurement indications obtained under specified conditions; it increases as random error decreases.

Sensitivity

The ratio of the change in an instrument's output reading to the corresponding change in the input value being measured.

Systematic Error (Bias)

A repeatable component of measurement error that remains constant or varies in a predictable manner, corrected through instrument calibration.

Repeatability

Measurement precision under conditions where successive measurements are performed under identical, constant operating conditions.

Reproducibility

Measurement precision under varying conditions, such as across different operators, test apparatuses, locations, or time periods.

Span

The mathematical difference between the upper and lower limits of an instrument's measurement range.

Calibration

The documented comparison of an instrument's output against a known standard under defined conditions to establish a relationship, calibration curve, or correction factor.

Metrological Traceability

An unbroken, documented chain of calibrations linking a measurement result back to national or international standards, where each link possesses a stated measurement uncertainty.

Primary Standard

An absolute reference measurement device, such as a soap bubble flow meter or frictionless oil piston, whose measurement does not rely on another flow standard.

Secondary Standard

A field measurement device, such as a rotameter, that must be periodically calibrated against a certified primary standard.

Zero Check

A verification procedure conducted prior to sampling to verify system leak tightness and establish baseline zero reading using clean air or an unexposed filter.

Aerodynamic Equivalent Diameter (AED)

The physical diameter of a spherical unit-density particle of $1\,\text{g/cm}^3$ that has the identical gravitational settling velocity in air as the particle being evaluated.

$$PM_{10}$$

Airborne inhalable particulate matter having an aerodynamic equivalent diameter equal to or smaller than $10\,\mu\text{m}$.

$$PM_{2.5}$$

Fine particulate matter with an aerodynamic equivalent diameter equal to or smaller than $2.5\,\mu\text{m}$, capable of penetrating deeply into the alveoli of the lungs.

Gravimetric Method

The standard reference method for measuring particulate matter concentration by drawing a known air volume through a filter and calculating mass concentration as $C = \frac{W_2 - W_1}{V}$.

Beta Attenuation Monitor (BAM)

An automated continuous particulate monitor that determines accumulated mass on a filter tape by measuring the attenuation of an electron beta-radiation beam.

TEOM (Tapered Element Oscillating Microbalance)

A real-time particulate mass monitor that measures mass deposition through the frequency shift of a hollow oscillating tapered element.

Cascade Impactor

A multi-stage aerodynamic sampling mechanism that separates airborne particles sequentially onto distinct impaction stages according to aerodynamic size.

Non-Dispersive Infrared (NDIR) Spectroscopy

The optical measurement principle utilized for continuous Carbon Monoxide ($CO$) detection based on selective light absorption at approximately $4.7\,\mu\text{m}$.

UV Fluorescence

The automated analytical technique used to measure Sulfur Dioxide ($SO_2$) via light emission excited by ultraviolet light at approximately $214\,\text{nm}$.

Chemiluminescence

The analytical detection technique used for $NO$ and $NO_x$, based on light emission resulting from the gas-phase chemical reaction between $NO$ and $O_3$.

UV Photometric Absorption

The standard physical measurement principle used to quantify Ozone ($O_3$) concentration by measuring ultraviolet absorption at $254\,\text{nm}$.

Becquerel ($\text{Bq}$)

The SI unit of radioactive activity, defined as one nuclear disintegration per second ($1\,\text{Bq} = 1\,\text{disintegration/s}$).

Absorbed Dose (Gray, $\text{Gy}$)

The amount of energy deposited by ionizing radiation per unit mass of matter, expressed in units of $1\,\text{J/kg}$.

Equivalent Dose (Sievert, $\text{Sv}$)

A radiation protection metric representing biological damage, calculated by multiplying the absorbed dose by radiation weighting factors.

ALARA

A foundational radiation protection principle directing that exposure levels must be maintained As Low As Reasonably Achievable, considering social and economic factors.

Type A Evaluation of Uncertainty

The evaluation of measurement uncertainty through statistical analysis of series of observed measurement results (such as sample standard deviation of the mean, $s / \sqrt{n}$).

Type B Evaluation of Uncertainty

The evaluation of measurement uncertainty based on scientific judgment, calibration certificates, manufacturer limits, and documented tolerances.

Expanded Uncertainty ($U$)

The product of the combined standard uncertainty ($u_c$) and a coverage factor ($k = 2$), defining an interval encompassing approximately 95% of the values.

Standard Operating Procedure (SOP)

A documented, step-by-step guideline detailing the standardized process for executing specific laboratory tests and quality controls.

Field Blank

An unexposed substrate identical to testing filters that is transported and stored alongside field samples without drawing air, used to detect and subtract handling artifacts.

Coefficient of Variation ($CV$)

A standardized measure of statistical dispersion representing relative variability, defined as the ratio of standard deviation to the mean ($CV = s / \bar{x}$).