Installation & Operation Manual
- Model VTS
Contents of this Manual are Subject to Change Without Notification
Page 20
TOOLS
Adjustment
➢
Balancer Offset
: Provides a simple tool for correlating the transmitter airflow
measurement to a field measurement in one step.
This offset is applied as an
Equal % Cal. Adj.
which does not overwrite the
factory calibration of the VTS. Using this function is not normally required
with the AccuStation (or advisable) and is only provided as a tool for the
Airflow Balancer to correlate the VTS airflow measurement to a field airflow
measurement. The graph below shows the effect the Equal % Cal Adj. has
over the entire operating range.
-10% Adj.=
-100 CFM change
-10% Adj. =
-40 CFM change
1000
400
800
600
200
0
Caution:
The Equal % Cal. Adj. should only be performed if the field
measurement is taken in accordance with ANSI/ASHRAE STD 111 with the
minimum requirements satisfied, otherwise the calibration adjustment
will reduce the accuracy of the VTS Transmitter.
Factory Cal. Airflow Meas. Curve
Airflow Meas. Curve with -10% Cal. Adj.
