Table 4-1 Terms And Definitions - Teledyne T640 Standard Operating Procedure

Term
Accuracy
Actual conditions
Bias
Calibration
Chain-of-custody
Coefficient of variation
Downtube
Flow adapter
Flow calibration device
Impactor
Leak check
Orifice flow rate check
device

Table 4-1 Terms and Definitions

The degree of agreement between an observed value and an accepted
reference value; includes a combination of random error (precision) and
systematic error (bias) components due to sampling and analytical operations.
The actual ambient temperature and pressure of a gas at the time its volume
(or volumetric flow rate) is measured.
The systematic or persistent distortion of a measurement process that causes
errors in one direction.
The act of adjusting an instrument after comparison with a standard.
Unbroken trail of accountability that verifies the physical security of
environmental samples and documented information.
A standardized measure of dispersion of a probability distribution or
frequency distribution. Defined as the ratio of the standard deviation to the
mean.
The vertically oriented tube that connects the PM
components inside the sampler case. To check the sample flow rate, the
sampler inlet is removed from the downtube and a flow rate standard is
connected in its place.
A tight-fitting connecting device, with an isolating valve, that is inserted in
place of the PM sampler inlet on the upper end of a sampler's downtube
2.5
and used to connect a flow rate calibration or audit device to check the
sample flow rate. In some cases, the device may also be used for leak
checks. Sometimes referred to as the flow shut-off valve.
A National Institute of Standards and Technology (NIST)-traceable flow
determining apparatus (also called a flow rate standard) that is attached to the
flow adapter device and used to assist in measuring and setting the volumetric
flow rate of air into the sampler.
An inertial particle-size separator. A PM
specially shaped inlet followed by an impactor that allows only PM of well-
defined size ranges to penetrate to the filter collection portion of the collector.
A test to determine if any post-air flow is passing the expected flow path of
the PM sampler.
2.5
One type of flow rate calibration or check device (transfer standard), based on
an established relationship between flow rate and pressure drop across the
orifice plate. An orifice's operating characteristics are determined in the
laboratory using a flow rate standard such as a soap film flowmeter. Orifice
devices generally require temperature and pressure corrections. Modern
orifice flow rate check devices generally make the needed temperature and
pressure corrections for the user. The orifice flow rate check device most
commonly used on PM
2.5
3
Definition
2.5
reference method sampler uses a
2.5
samplers may also be called a venturi.
DEP 03-21
Revision No. 0
November 2017
sampler inlet to sampler