Capture Hood Field; Correction Factors - TSI Alnor LoFlo Balometer El Manual Del Propietario

Model 6200 LoFlo Balometer
HISTORY:
It is well known that capture hoods are susceptible to
diffuser styles that are different from that upon which
they were calibrated. Understanding that these
productivity tools may require adjustment in the field,
®
the LoFlo Balometer Capture Hood is equipped with
two separate sets of field programmable correction
factors, "FLD A" and "FLD B", that allow for a field
calibration of the instrument to different diffusers.
DETERMINING FIELD PROGRAMMABLE

CORRECTION FACTORS:

Correction factors are simply the relation between the
actual volume flow rate and that which is displayed on
®
the LoFlo Balometer Capture Hood. The actual
volume flow rate is most accurately established through
performing a duct traverse. The correction factor is then
determined as the ratio of the actual volume flow rate
divided by the volume flow displayed on the LoFlo
®
Balometer Capture Hood set in the factory calibration
setting (default from factory). The number obtained is
used as the multiplier for that particular diffuser.
Example:
Duct Traverse yields 120 CFM
®
LoFlo Balometer Capture Hood in Supply Mode
with Vents Closed yields 107 CFM
Correction Factor = 120/107 = 1.121
Because there are no decimal points available for the
correction factor values, this number will be
programmed into the LoFlo Balometer
If all available operating modes of the LoFlo instrument
are to be used, a separate multiplier must be determined
for each mode. The four available modes are:
• Supply, Vent Closed (10-150 CFM)
• Supply, Vent Open (150-500 CFM)
• Return, Vent Closed (10-150 CFM)
• Return, Vent Open (150-500 CFM)
12
APPENDIX B
®
Capture Hood Field Setting Instructions for
User Programmable Correction Factors
®
unit as 1121.
PROGRAMMING THE CORRECTION
FACTORS TO THE INSTRUMENT:
Once the multipliers have been determined, the
correction factors are programmed to the LoFlo
instrument using the following steps:
1. Turn the instrument off.
2. Press and hold the range selector button
simultaneously switching the instrument on. The
display will show "FAC" with the seven segment
characters, indicating the unit is in its default factory
setting.
3. Use the supply/return button
the available storage fields, "FLD A", "FLD B" or
"FAC". Use the handle hold switch to select the
desired field. If "FLD A" or "FLD B" are selected,
the field letter chosen will be displayed at the upper
right of the LCD throughout the programming
cycle. Note that the factory calibration setting,
"FAC", cannot be altered.
4. Once the desired storage field has been selected, the
unit will display the symbols for the Supply, Vent
Closed mode, along with the current correction
factor programmed for that mode. The factory
default coefficient for each mode within both of the
programmable storage fields is 1000 (recall that
decimal points are not available, and thus the stored
value of 1000 is actually 1.000). Use the
supply/return button to increase the coefficients
value, or the range selector button to decrease the
value as desired. When the correct multiplier is
displayed, press the handle hold switch to store the
value. The display will then cycle to the Supply,
Vent Open mode (indicated by the appropriate
symbols), again allowing for increasing/decreasing
of the multiplier to the desired set-point as described
above. This process will repeat for the remaining
two operating modes (Return, Vent Closed; and
Return, Vent Open).
5. Once a correction factor has been selected and
stored for each of the four operating modes, the unit
will proceed into operation using the programmed
coefficients of the storage field that was selected.
Once again, use of "FLD A" or "FLD B" will be
indicated by the field letter chosen being displayed
at the upper right of the LCD throughout the
operating cycle. The selected storage field will
while
to cycle through