TSI Instruments ALNOR LOFLO BALOMETER Series, Owner'S Manual

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12
APPENDIX B
Model 6200 LoFlo Balometer
®
Capture Hood Field Setting Instructions for
User Programmable Correction Factors
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
®
unit as
1121 .
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)
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
while 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 to cycle
through 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).