Biomedical Engineering Reference
In-Depth Information
Table 3.4
(Continued)
Regulation
Calibration Predicate
Rule
SOP Predicate Rule
21CFR820.72(a) Each manufacturer shall
ensure that all
inspection, measuring,
and test equipment,
including mechanical,
automated, or electronic
inspection and test
equipment, is suitable
for its intended purposes
and is capable of
producing valid results.
Each manufacturer
shall establish and
maintain procedures
to ensure that
equipment is routinely
calibrated, inspected,
checked, and
maintained.
21CFR1271.200;
§ 1271.180
(c) You must routinely
calibrate according to
established procedures
and schedules.
(a) You must establish
and maintain
procedures.
concepts of reliability, precision, and accuracy. FDA
regulations require that equipment be calibrated according
to written procedures that include measurement standards
for precision and accuracy.
20
Consider a balance, an instrument used to measure the
weight of the product. Several questions arise: Is it a precise
instrument? Is it an accurate instrument?
Regarding
precision
, FDA has stated that it “indicates a
relative degree of repeatability, i.e., how closely the values
within a series of replicate measurements agree with each
other.”
21
In general, reliability is inversely related to precision.
The National Institute of Standards and Technology has
defi ned
accuracy
and
bias
as follows:
Accuracy is a qualitative term referring to whether there
is agreement between a measurement made on an object
and its true (target or reference) value. Bias is a
