Changes require recalibration Remember that you must calibrate your device each time you repair or replace the pump or tubing, or use a different product.
Editor’s Note: A new publication from Purdue University Extension entitled Calibrating for a Liquid Termiticide Application, co-authored by Fred Whitford, Director of the Purdue Pesticides Program, is now available. The guide describes the process for calibrating termite application equipment so that applicators apply the correct concentrations and volumes to structures, based on product label instructions. Download for free or order from https://ppp.purdue.edu/resources/ppp-publications (search PPP-144). The following excerpt provides a visual guide to calibration.
You can graphically determine the total amount of gallons of solution needed. With most termiticide products, users need to know the outside linear dimension and depth of the footer to determine how much termiticide is needed to treat the structure. The chart should indicate the length of the wall and the depth of the baseboard on each section of the exterior wall (see image below).
For example, a wall is 20 feet long and the footer is 3 feet deep. If the application rate calls for 4 gallons per 10 linear feet x depth of footer, that area will require an application of 24 gallons of solution. By adding up the gallons used for each section, users can calculate the total amount of product they need for the entire structure.
KNOW THE DEVICE’S GALLONS PER MINUTE. The normal target flow for most termite application equipment is 2 gallons per minute. To check your flow rate, all you need is a graduated gallon bucket and a stopwatch. To determine the flow rate, pour the liquid from your injector wand or gun into the measuring bucket for one minute. You can also collect the liquid for 30 seconds and multiply the amount by 2. Alternatively, you can use a stopwatch to see how long your termiticide rig takes to apply 1 gallon.
Note the pressure of the pump at the beginning of the collection. If the rate is more or less than 2 gallons per minute, adjust the pump pressure. The lower the pressure, the lower the flow and vice versa – so increasing the pressure increases the product flow. Continue adjusting the pressure until the tips each dispense 2 gallons per minute.
Record the operating pressures separately for each of the application tools to ensure the unit is discharging 2 gallons per minute. Note the specific pressures for each tool when using it, and then set the proper pressure before beginning treatment. In-line flow meters are also available for some termite plants, but they may need to be calibrated. You should also routinely calibrate these gauges using this simple method to verify their accuracy.
