Prior to measuring grass cover, enter or select the required pasture cover calculation formula (examples can be found on the Feed Budget Cycle page).
On entering a new paddock turn on the Android App and the EC20 platemeter, pair up the counter with the App and select the paddock to be read. The EC20 Platemeter is lowered vertically onto the grass, with the shaft dropping through to rest on the ground, leaving the plate supported by the grass.
The area and weight of the plate have been carefully calibrated for accuracy. The taller and denser the grass, the further off the ground the plate rests. Grooves on the handle allow combined grass height and density to be measured in ½ centimeter intervals (‘clicks’).
The EC20 Electronic plate counter will record the position of the plate relative to the ground in centimeters, instantly displaying the result in terms of grass height and calculated pasture cover on the Android App (this also records the GPS location of that plonk which will allow you to export the kml file and view in Google Earth).
Walk across the paddock, taking typically 30 to 50 sample readings. At the end of the paddock walk select “done” on the Android App. Repeat the process for each paddock being measured.
Example pasture cover equations for entering into the Android App can be found in the handbook under formulas or on the Feed Budget Cycle page.
Rising plate platemeters have been developed over a number of years to be simple, effective and reliable. They are second only to cutting drying and weighing pasture for accuracy as they allow for various pasture densities. To retain this accuracy and ensure many years of trouble-free use a little maintenance is recommended.
When fitting or removing the plate it is easier if the counter is moved along the grooved rod a little.
After assembling the plate onto it, move the plate up and down a few times to ensure no binding occurs. If its movement is restricted (e.g. there are tight spots) the reason must be found and cured before the meter is used.
We have some sad examples returned to us for repair. The worst have been subject to chemicals — often fertiliser, maybe out of the paddock, water troughs or in the shed. If you suspect chemicals or other contaminants have got to the meter a good wash in fresh water and subsequent dry out is required.
Remove the plate and wash it clean. Mud or extra weight on the plate is undesirable.
Wash/wipe and dry the area around the bottom of the meter. Move the counter fully up so that all dirt and accumulated grass can be wiped or washed away especially around the lower part of the grooving on the shaft.
Occasionally, maybe every second month, move the counter up and apply light oil (CRC, WD40 or similar) to the grooved rod. Wipe all excess oil off.
These are precision meters — look after them.
The operator’s Handbook contains a wealth of information on all aspects of feed budgeting and the use of a rising plate platemeter, including the various formulas or equations that can be used.
Download a copy of the model applicable handbook from the Support page.
A full parts list for the Jenquip Electronic Platemeter is available as a downloadable PDF.
IMPORTANT NOTE: 99% of problems are due to the electronic counter being out of calibration.
If in doubt, it is worth Zero Calibrating the meter just to make sure it is correct. Refer to specific model handbook for Zero Calibration instructions.
Please check the following before contacting Jenquip:
Check your technique to ensure you are not ‘rolling’ the meter. The meter should always be placed on the ground at 90 degrees to it. This can easily be achieved while walking especially if it has a ball knob as a handle.
Electronic counter cog not counting correctly:
|Cog not aligned correctly on the shaft.||Re-align the cog.|
|Cog worn.||Replace the cog with a new part ordered from Jenquip.|
Meter plate not running freely:
|Alloy shaft is bent.||Straighten, or order a replacement part from Jenquip.|
|Grass or soil build-up inside the black tube.||Clean the Platemeter.|
|Grooves on alloy shaft have become filled with grass or soil.||Clean the Platemeter.|
Specific notes for Electronic Platemeters
Before recalibrating, check for any potential physical problems listed in the table below which may have caused the meter to need recalibrating.
There is no visual display:
|The counter is not turned on.||Turn on.|
|The battery is flat.||Replace battery.|
|If you have just changed a battery you may have damaged the battery snap (clip to top of the battery).||Service – send to Jenquip.|
The counter battery light is changing colour and eventually turns off:
|This is normally due to a low battery. The counter requires a given level of power to operate correctly.|
The “Battery Status” LED shows green for the first half of the battery life.
As the battery becomes weaker, the LED will gradually change to orange, and then to red when it is at 6V. From 6V to 5V, the LED will slowly flash red as there is only about one hour of life left. A good quality Alkaline battery could last around 28 hours or even longer. Below 5V, the product will play a tune and turn off.
|Recharge the battery.|
Battery may be due for replacement.
Requires electronic service.
The counter does not “beep” when taking a reading:
If the counter does not beep, it means that the counter does not know where the bottom is — therefore does not record the ‘plonk’. Zero calibrate the meter. Refer to specific model handbook for zero calibration instruction.
|The cog has wound off.||Replace – order a replacement cog from Jenquip.|
|Potentiometer damaged (the potentiometer is the shaft part that drives the cog).||Send to Jenquip for service and repair.|
Note:Under no circumstances should you apply CRC or a light oil to the potentiometer. It is a dry bearing and any lubricant will render the potentiometer useless.
|Check the cog is running smoothly on the shaft.||Re-assemble the Platemeter.|
If the counter is mounted too close to the alloy shaft there will be quite a lot of friction when taking a reading.
If the counter is mounted too far away from the alloy shaft, the cog is liable to jump a notch easily.
Counter Readings do not seem accurate:
|The counter is like a calculator – it does not give false readings under normal circumstances.||Check the equation being used is correct and the calibration has been correctly set (zeroed).|
Note: In New Zealand there are a number of standard equations published by various organisations. These reflect regional pasture types. If you wish to change an equation or select alternative species you will need to contact your consultant.
Traditionally the equation of pasture height x 158 plus 200 was used. However, there has been a series of equations produced to reflect changes in pasture types and physiological state (vegetative, flowering, seed head) which can alter DM levels in the paddock.
A more accurate calibration can be achieved by taking cuttings or your consultant may be able to advise you on the most appropriate equation for your situation. This particularly applies to pastures under irrigation.