RIO BLANCO COUNTY CALIBRATION SERVICES

The Rio Blanco County Weed Department can assist you in calibration of your spraying equipment. Below are some formulations to assist you in calibrating different types or equipment.

If you have boom type sprayers please call the County Weed Department for further information.

SPRAYER CALIBRATION FOR HAND GUNS

Calibration of a backpack sprayer or a hand gun sprayer need not be intimidating. There is a simple formulation that can take the guesswork out of applying herbicides.

Many people frequently ask how much chemical do I need to add to my 4 gallon (or what ever size it may be) sprayer to control weeds. While I wish I had a magical formulation so I could just give you a rate to mix it at, it's not that simple. Some people will mist the plants, while others will try to drown the plants. Each chemical product will have a different rate of application. And many time's different plants will require different rates of application. So you see there is no magical formulation that can do it all. But there is a solution that is simple and quick.

To calibrate:
1. Measure an area 18.5 ft by 18.5 ft in the target area.
2. Spray the measured area with WATER ONLY and record the number of seconds required to cover the area uniformly while spraying constantly. (Do NOT stop spraying during step number 2)
3. Measure the amount of water delivered to the test area by spraying into a container for the same amount of time it took to cover the test area. Use an old measuring container and keep it for future calibrations.
4. The amount of water collected in fluid ounces equals spray volume in gallons per acre. Example if it took two minutes to cover the test area, spray into your measuring container for two minutes only. If you collect 30 ounces in that time period the amount of water needed to spray one acre would be 30 gallons.
5. Refer to the chart below for the amount of herbicide to mix at the spray volume indicated by the calibration procedure. This chart contains the amount of herbicide to mix when the application rate is 1 quart per acre. For a rate of 1/2 quart per acre (1 pint) divide the amount in the table by 2. For an application rate of 2 quarts per acre multiply the table value by 2, and so on.

To apply the equivalent of 1 quart of herbicide per acre at the spray volume indicated, mix according to the following chart:

Remember the sprayer is now calibrated for your misting or drenching technique and anyone else using the sprayer should recalibrated for their own technique. Always read and follow the entire product label when applying any pesticide.

3teaspoons level (tsp) = 1 tablespoon level (tbs) & 2 tablespoons level = 1 oz.

SPEED CALIBRATION
Many speed odometers on tractors and trucks are not accurate at low speeds. To determine your correct speed use the following formula:

1. Stake off a distance of 88 feet in the area you are going to be treating.
2. Select the vehicle gear and throttle setting to be used.
3. Clock the seconds required to drive the 88 feet from a running start. Maintain a constant speed throughout the entire course. Drive the course at least 3 times and determine the average time in seconds it took you to travel the course.
4. Divide the time in seconds that it took to travel the course into 60; the answer is the miles per hour for those field conditions. Conditions can vary from field to field. Soft ground can slow your speed and hard ground can increase your speed.

USEFUL MEASUREMENTS FOR CALIBRATION

Linear measurement:
5,280 feet = 1 mile

Measure of surface area:
144 square inches = 1 square foot
9 square foot = 1 square Yard
43,560 square foot = 1 acre

Liquid measure:
3 teaspoons (level) = 1 tablespoon or 1/2 ounce
2 tablespoons = 1 ounce
8 fluid ounces = 1liquid cup or 16 tablespoons
2 cups = 1 pint
16 fluid ounces = 1 pint
2 pints = 1 quart
32 ounces = 1 quart
4 quarts = 1 gallon
128 ounces = 1 gallon

If you have any problems or a specific need your not sure about call the Rio Blanco County Supervisor.