Chapter 4: How To
21
Select/Set a K-factor for a Tool
It is possible to enter K-Factors to adjust the calculations of the velocity and flow measurements.
For Pitot Velocity, Pitot Flow, Air Flow Probe Flow, Air Flow Probe Velocity and Velocity Matrix, the
K-Factor is simply multiplied by the calculated velocity or flow in order to get the displayed value. For
these Tools, use of a K-Factor is optional and setting the K-Factor to 1.0 will turn it off. The K-factor
range for these Tools is 0.500 to 1.500.
For the Diffuser Flow Tool (Flow from Pressure and K-factor), the use of a K-Factor is mandatory. The
displayed flow for this tool is the square root of pressure times the entered K-Factor. The K-factor range
for this Tool is 0.001 to 9.999.
You can only enter a K-factor if you have selected a Tool that can use a K-factor. The Pressure Tool does
not use K-factors.
To select or set a K-factor, proceed as follows:
1.
Press
to display
CHANGE Test ID.
2.
Press
X
until
K-FACT
appears.
3.
Press
.
The K-factor currently being used flashes on the display.
4.
Press
X
to scroll through the available K-factors or turn the K-factor Off. The instrument lets you set
four K-factors for each tool that uses a K-factor.
5.
If you want to change the value of a K-factor, use
S
and
T
to change the K-factor to the value
desired.
6.
Press
to accept the desired K-factor.
K-FACT
is displayed.
7.
You can repeat steps 3–6 to select and/or adjust other K-factors for the Tool. Once you set a K-factor
it remains set until you change it.
View/Set Standard Pressure and Temperature
Temperature and barometric pressure are used for calculating some of the flow and velocity
measurements shown by this instrument, as follows:
For the Pitot Flow, Pitot Velocity, Air Flow "Flow", Air Flow Velocity, Capture Hood, and Velocity
Matrix, the instrument uses barometric pressure measured by an internal barometric pressure sensor.
For these tools, the instrument will also use temperature measured by a temperature sensor plugged into
the side of the meter.
The hood base temperature sensor, accessory temperature probe, or the accessory temperature/humidity
probe can be used for supplying this temperature measurement. If none of these temperature sensors are
plugged in, you will need to enter the flow temperature using the
STP.SET
menu.
For the Diffuser Flow tool (Flow from Pressure and K-factor), temperature and barometric pressure are
not used for calculating flow. Therefore the user is not required to enter a temperature for this tool.
