Accutrol Apex Premier, Installation, Operation & Maintenance Manual, Page: 14 / 61

T-APM - Apex Premier F
UME
H
OOD
M
ONITOR
T-APM 0133MAN00015 - Rev J ECN - JUL 2017
Page 14 of 61
Calibration of the APM
Two-Point Calibration Procedure
The Two-Point Calibration Procedure is recommended for most fume hood applications including
constant volume and variable volume with setback and volume limits. The Two-Point calibration
procedure requires two face velocity measurements to be taken and entered into the APM, one at a high
face velocity and another at a low face velocity. The Two-Point Calibration process will result in
correlati
ng the internal sensor’s “offset” and “slope” to match the measured values provided.
Step 1: Enable Two-Point Calibration Mode
With the touch screen enabled and correct password entered, press CAL MENU reference
[SCREEN 1]
and
[SCREEN 1K]
. Using the up and down arrows [

or

] select TWO-POINT CALIBRATION .
Step 2: Move Sash to Full Open (Low Velocity Point)
Following the instructions on the APM
[SCREEN 2K]
, open the sash(es) to the full open position to achieve
a low face velocity calibration point. If the fume hood has sash stops available, defeat them and open
past the stops. The goal is to achieve the maximum operating open area of the fume hood face. Press
the screen to confirm sash is in position.
Step 3: Traverse Hood Face at Max. Open Sash (Low Velocity Point)
Perform a face velocity traverse, with a calibrated instrument, across the open area of the fume hood
face. Once the average face velocity reading is obtained, press the touch screen
[SCREEN 3K]
.
Step 4: Enter Traversed Reading (Low Velocity Point)
Using the plus and minus signs [ + or - ] on the touch screen [SCREEN 4K] ; enter the value obtained in
the previous step. Note: By pressing and holding the sign, the number will first change at a slow rate then
at a fast rate automatically. Depressing the
RESET
button will return the velocity value to the factory
default setting.
Press the
ACCEPT button when the desired value appears in the velocity box and step a few feet away
from the hood. After a 5-second delay, the APM will now acquire 15 data points while displaying the
measured values on the LCD screen
[SCREENS 5K & 6K] . Observe the display and confirm that the
values are consistent and do NOT vary by more than +/- 5 fpm (0.02 m/s) . If the values are within
limits then proceed to the next step. If the values are unstable, then STOP calibration process and
determine the cause of problem before proceeding.
Step 5: Move Sash(es) to Min. Open Position (High Velocity Point)
Following the instructions on the APM [SCREEN 7K] , move the sash(es) to a minimum working sash
position. Do NOT close the sash(es) completely
. The minimum working sash height is typically 6” to
12
” open (15.2 to 30.5 cm). Press the screen to confirm sash is in place.
Step 6: Traverse Hood Face at Min. Sash Position (High Velocity Point)
Perform a face velocity traverse, with a calibrated instrument, across the entire open area of the fume
hood face. Press the touch screen
[SCREEN 8K]
to confirm measurement is complete.
Step 7: Enter Traversed Reading (High Velocity Point)
Enter the measure value
[SCREEN 9K]
using the same process as described in Step 4.
Step 8: Completion of the Two-Point Calibration
The Two-Point Calibration procedure has been completed. The final screen [SCREEN 10K] in the
calibration process allows you to either EXIT or CONTINUE TO CONFIG MENU . Selecting EXIT will
return the APM to monitor mode, while depressing the
CONTINUE TO CONFIG MENU
option will bring
you into the configuration menu which will allow configuration of the APM.