Product Overview

FlexStat (General) 8 Application Guide, Rev S
Calibrating a (Temperature) Sensor
This section describes checking and calibrating the internal tempera-
ture sensor, but other analog sensors can be calibrated in an analogous
manner. For maximum accuracy, wait at least a half hour after initial
power-up before checking or performing calibration of the INTER-
NAL temperature sensor!
NOTE: Mounting location can greatly aect accuracy! See Mounting
Considerations on page 4. Other issues may aect tempera-
ture accuracy—see the Troubleshooting section in the FlexStat
Operation Guide.
NOTE: With rmware version R2.0.0.21 and later, a FlexStat’s tem-
perature reading starts out too “cold” and becomes “warmer”
until stabilizing at maximum accuracy. The dierence is more
pronounced in the BAC-13xxxx/14xxxx CO
2
models.
NOTE: With R2.0.0.13 and later rmware, Fahrenheit temperature
values on the display change in whole degree increments by
default, and Celsius values change in 0.5° increments. Chang-
ing the default No to Yes will show tenths of a degree values for
both scales. (This does not aect setpoint adjustments, which
are always in whole degree increments for Fahrenheit and half
degree increments for Celsius.) For calibration purposes, tem-
porarily changing the No to Yes for Show Temp Tenths may be
desirable.
To CHECK space temperature calibration:
1. After an initial power-up, wait at least a half hour before calibrating
the FlexStat.
2. Carefully position an accurate thermometer or temperature probe
next to the FlexStat and (after sucient time for the thermometer or
probe to stabilize) compare readings.
NOTE: Body heat can aect the temperature of the FlexStat and/or a
thermometer.
3. If there is an undesirable discrepancy, the space temperature calibra-
tion oset value of AI1 (the internal space temperature sensor) can
be changed in the FlexStat menu or BACstage or TotalControl.
The calculation is New FlexStat Oset = Existing FlexStat Oset + Meter
Temp – FlexStat Temp. For example, if the FlexStat is reading 1.1 degrees
too high, the New FlexStat Oset = [0 (Existing FlexStat Oset) + 75.1
(Meter Temp) – 76.2 (FlexStat Temp)] = –1.1.
MAIN MENU
ABOUT
ADVANCED
ALARM
DATE/TIME
DCV
SCHEDULE
SETPOINTS
ADVANCED
LIMITS
LOOPS
RESTART/RESTORE
SECURITY
TREND LOGS
TEST
USER INTERFACE
USER INTERFACE
DISPLAY BLANKING: NO
INACTIVITY (SECS): 60
ROTATION VALUES
SHOW TEMP TENTHS:
MODE: STANDARD
NO
NOTE: For calibrating a BAC-14xxxx CO
2
sensor with gas, see CO2
Sensor Calibration on page 26.
NOTE: In rmware versions before R1.3.0.4, Fahrenheit readings had a
default oset of 32. The method of temperature value calcula-
tion then changed, and the default oset is now 0.