Dwyer Instruments Mark II 40 Series User manual

  
 

.
 
-L2
" -
 
 t 

 
 

       
      
       
    
    
      
    
     
 
     
     

     

   
        
     
     
    
 
   
       

 
      
     
   I


 

 

 

 


    
 
 

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com

Static ressure Indicator: Using the 1/8˝ NPT
tubing adapters provided, make a static pressure
connection to the duct at the desired location.
Using either the tubing provided or a longer
length if necessary, connect the pressure sensor
to either the high (left) or low (right) pressure
connection of the gage, depending on whether
the static pressure is positive or negative
compared to atmosphere. Where air velocities in
the duct are 1000 ft. per minute or higher, static
pressure error may be induced unless a static
pressure tip is used.
Air Filter Gage: Mount the gage within 4-1/2˝ of
the filter bank and install a 1/8˝ NPT tubing
adapter in the duct on each side of the filter
element. Run the tube from the fitting on the
discharge side of the filter to the low pressure
(right) gage connection and the tube from the
upstream side of the filter to the high pressure
(left) connection. Remove the paper backing
from the green and red arrows and install the
arrows on the face of the manometer adjacent to
the indicating tube to indicate clean and dirty filter
readings.
Air Velocity Indicator: A pitot tube is required for
air velocity readings and care must be taken in
installations to insure accuracy. Select a location
for the pitot tube with smooth straight sections of
duct at least 8-1/2 diameters upstream and 1-1/2
or more diameters downstream. Install the pitot
tube so it is centered in the duct with the tip
directed into the air stream. The right angle pitot
tube connection is connected to the low pressure
(right) gage connection. The straight pitot tube
connection is connected to the high pressure
(left) gage connection. Velocity reading now
indicated on the gage is the center or maximum
air velocity in the duct. For average velocity
across the full area of the duct, multiply by a
factor of .9. The velocity indicated is for dry air at
70°F (21.1°C), 29.9˝ barometric pressure, and a
resulting density of .075 pounds per cubic foot.
For variations from these standard conditions,
corrections may be based upon the following
formula:
Air Velocity (FPM) = 1096.7
Where Pv = velocity pressure in in./H
2 O
D = air density in lbs. per ft
3
D = 1.325 x
Where Pb = barometric pressure in inches of
mercury
T = absolute temperature (indicated °F
+ 460)
To determine the volume of air flow in the duct in
cubic feet per minute, multiply air velocity in FPM
times the cross-sectional area of the duct in
square feet.
Pb
T
Pv
D
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com

©Copyright 2015 Dwyer Instruments, Inc. Printed in U.S.A. 8/15 FR# 440433-00 Rev. 5
DWYER INSTRUMENTS, INC.
.O. BOX 373
MICHIGAN CITY, INDIANA 46360, U.S.A
Model
40-1
40-1-AV*
41-2
41-2-AV*
40-250 a
40-250-AV*
41-600 a
40-25 mm
41-60 mm
Range
.10-0-1.00˝ w.c.
0-1.10˝ w.c.
0-4200 fpm
.20-0-2.400˝ w.c.
0-2.50˝ w.c.
0-6300 fpm
10-250 Pa
0-260 Pa
0-21 mps
20-0-600 Pa
0-26 mm w.c.
0-60 mm w.c.
Minor Grades
.01˝ w.c.
.01˝ w.c.
varies
.02˝ w.c.
.02˝ w.c.
varies
2 Pa
2 Pa
varies
5 Pa
2 mm w.c.
5 mm w.c.
Indicating Fluid
.826 sp. gr.
(red fluid)
.826 sp. gr.
(red fluid)
1.910 sp. gr.
(blue fluid)
1.910 sp. gr.
(blue fluid)
.826 sp. gr.
(red fluid)
.826 sp. gr.
(red fluid)
1.910 sp. gr.
(blue fluid)
.826 sp. gr.
(red fluid)
1.910 sp. gr.
(blue fluid)
O ERATING RANGES
* Pitot tube required at additional cost.