Calibration
HI and LO Multi-Point Calibration
Thermo Fisher Scientific
Model 48
i
Instruction Manual
4-7
3.
Latest copy of the
Quality Assurance Handbook for Air Pollution
Measurement Systems
1
should be consulted to determine the level of
acceptance of zero and span errors.
For detailed guidance in setting up a quality assurance program, refer to
the
Code of Federal Regulations and the EPA Handbook on Quality
Assurance
.
The instrument can also be calibrated using a dual three-point calibration.
The calibration points are divided into a “low” range and a “high” range
consisting of three points each:
●
Cal point 1
●
Cal point 2
●
Cal point 3
The customer defines the ranges and Thermo Fisher Scientific recommends
the following calibration points for each range:
●
Cal point 1: 80% of range
●
Cal point 2: 50% of range
●
Cal point 3: 20% or range
Note
If performing a multi-point calibration after a “bad” calibration or
changing ranges it is recommended to start off with default values for the
Cal point coefficients.
▲
To set default values, from the Main Menu select Service Mode >
Hi
Multi-Point Cal
or
Lo Multi-Point Cal
. From Hi or Lo Multi-Point Cal,
select
Default Coef
and press
. The instrument will automatically
reset the default values.
Use the following procedure to adjust cal points 1, 2, and 3.
1.
Adjust the zero air flow and the CO flow from the standard CO
cylinder to provide a diluted CO concentration of approximately 80%
of the upper range limit (URL) of the instrument. The total air flow
must exceed the total demand of the analyzer connected to the output
manifold to ensure that no ambient air is pulled into the manifold vent.
The exact CO concentration is calculated from:
HI and LO Multi-Point
Calibration
Default Coefficients
Cal Point 1, 2, and 3
Adjust
