TeeJet 844-E Sprayer Control - Manual (Page 33)

29
98-70006-ENUS R4
844-E Sprayer Control
ChaptEr 7 - Flow MEtEr Calibration
The flow meter supplied with your system has been calibrated at the factory and under normal circumstances there may be no need to re-calibrate
it. However, the factory calibration setup may not reflect specific sprayer plumbing. Before spraying actual chemicals, the flow meter should be
checked for proper calibration. Also, the flow meter is made up of moving parts and can wear over time. If you feel that your flow meter is worn,
you can re-calibrate your flow meter using the 844 console. To do so, use either of the following methods:
Method 1 – Known Volume
Step 1 – Known Value
Select a known volume of water (n) that you will pump through the flow meter. In these steps, 10 US gallons (38 liters) {8 Imperial gallons} will be
used as an example. The specific volume you use is not important, although larger volumes generally produce more accurate results.
Step 2 – Programming Calibration Number
Go into the System Setup mode and advance to the flow meter calibration number step (flashing turbine at the top of the display). In this
programming step, enter (n) 10 US gallons (38 liters) {8 Imperial gallons} as the calibration number. Exit the System Setup mode by pressing and
holding the key for five seconds.
Step 3 – Resetting Volume Counter
Reset the total volume number that is displayed in the lower right portion of the display. (Display alternates between Ac (Ha) covered and the
volume sprayed through the flow meter). To reset this number, press and hold the Plus key and Minus key simultaneously for three (3)
seconds or until you see the values reset to zero.
Step 4 – Spraying Known Volume
Engage the pump on the sprayer, flip the Master boom section of the 844 to “ON” (make sure at least one boom section switch is on), and pump
exactly (n) 10 US gallons (38 liters) {8 Imperial gallons} through the flow meter. When the known volume is reached, shut the Master boom switch
“OFF”.
Step 5 – Entering in New Flow meter Calibration Number
The number that is displayed in the lower right corner of the display is your new flow meter calibration number. Record this number, enter the
System Setup mode and advance to the flow meter calibration number step. Enter the new value from your test into this step and then exit the
System Setup mode.
Step 6 – Double-checking the New Value
Double-check your new value by spraying a larger volume of water, such as 100 US gallons (378 liters){83 Imperial gallons} through the flow
meter. Before spraying the larger volume, make sure to reset the memory counters by depressing and holding the Plus key and Minus key
simultaneously for three (3) seconds.
NOTE: After double checking the new calibration number, if you find that the volume shown on the display of the 844 is more than +/- 3% in error,
change the flow meter calibration number in the System Setup mode by the % difference it is in error.
Method 2 – Known tip Size Method
Step 1 – Check Tip Size
Determine what size tip is on the sprayer. An actual flow collection should be done on a representative sample to ensure the tips are not worn. To
do this, set the boom pressure at 40 psi (2 bar). This must be pressure at the tips (i.e. use manual pressure gauge mounted on the boom). Collect
flow for 1 minute from 1 tip.
Example: xR8004 tip should spray 0.4 gallons in 1 minute (1.29 LPM) {0.32 Imp gal}
Step 2 – Count Tips
Count the total number of tips to be used for measure. You can use 1 boom section, 2 boom sections, etc.
Example: Boom Section 1 has 10 tips
Step 3 – Calculated Flow
Multiply the number of tips to be measured by the size (or individual flow rate) of each tip.
Example: 10 tips x 0.4 gPM (1.29 LPM) {0.32 Imp gPM} = 4gPM (12.9 LPM) {3.2 Imp gPM}