the detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventors . the detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention . however , it will be apparent to those skilled in the art that the present invention may be practiced without these specific details . fig1 is an electrical overview of an embodiment of the invention . fig1 shows tractor 21 and calibration console position 1 located in the cab of tractor 21 . tractor 21 tows toolbar 23 , which toolbar may comprise a plurality of individual ground openers ( not shown ), collectively referred to herein as a seeder . the seeder in turn tows air cart 25 , which air cart comprises a metering system having at least one meter , for example , as shown in fig3 a and as described in more detail below . air cart 25 further comprises at least one tank or hopper ( not shown ) for carrying at least one product such as seed or fertilizer . as can be seen in fig1 , console position 1 is electrically connected to console position 2 by electrical harness 24 , which may comprise tractor harness 26 , toolbar harness 30 and air cart harness 34 . the distance between the air cart 25 and the tractor 21 can be anywhere from 40 - 50 feet or more and thus the distance an operator must travel between the air cart and tractor cab is significant , in particular when calibrating a metering system comprising more that one meter . with reference now to fig2 , an embodiment of the invention is shown in more detail . calibration console 22 comprises input pad 31 , screen 33 and an internal microprocessor which can be calibrated and then used to monitor the feed rate and / or dispensing rate of the product . in one embodiment , the calibration console 22 can also be used to adjust the feed rate of the product . as previously mentioned , electrical harness 24 may comprise tractor harness 26 , toolbar harness 30 and air cart harness 34 , whereby tractor harness 26 is attached to toolbar harness 30 via tractor hitch junction 28 and toolbar harness 30 is attached to air cart harness 34 via air cart junction 34 . at the tractor end of electronic harness 24 is console port 1 ( 36 ) and at the air cart ( or metering system ) end of electronic harness 24 is console port 2 ( 38 ). thus , calibration console 22 can be moved to either position . attached to air cart harness 34 is at least one meter rotation sensor 120 , the number of meter rotation sensors corresponding to the number of meters there are in the metering system . as will be explained in more detail below , meter rotation sensor 120 senses the number of rotations of each meter that is rotated during metering calibration . the meter may be rotated via a meter roller shaft that is either manually rotated by means of a crank or hydraulically or electrically rotated as is known in the art . thus , meter rotation sensor 120 is operably connected to calibration console 22 having a microprocessor so that the number of rotations of the rotatable meter needed to dispense a particular weight ( or unit ) of product is automatically inputted into the calibration console . in some embodiments , a second sensor is provided , ground sensor 170 . in one embodiment , ground sensor 170 senses the distance traveled by a ground wheel by sensing the number of rotations of the wheel and inputting the data into the calibration console , which converts the number of wheel rotations into distance and then acres or hectares , which accounts for the width of the seeder . thus , the calibration console can also calibrate the weight of product dispensed per linear distance traveled by the seeder to give an application rate in lbs or kg per acre or hectare of land when taking into account the overall width of the seeder . in the alternative , a radar sensor as known in the art can be used to determine distance . an example of a metering system comprising at least one meter 10 for use with air seeders for dispensing product from at least one product tank or hopper for delivery to the soil is shown in fig3 a and 3 b . the at least one meter and at least one hopper can be located directly on the air seeder or can be towed behind an air seeder on an air cart as shown in fig1 . air seeders that can separately deliver two products , for example , seed and fertilizer , generally employ a primary pneumatic distribution system 160 , as shown in fig3 a and 3 b , which may deliver metered seed and fertilizer separately from separate product tanks or hoppers 140 through one of two sets of primary distribution lines 162 , 164 . this arrangement is commonly referred to as a “ double shoot ” and allows for both products to be simultaneously , but separately , applied to a field . alternatively , it is understood that a metering system may also comprise a primary pneumatic distribution system of a “ single shoot ” configuration , where only one product tank or hopper is involved and only one set of primary distribution lines is needed . with reference now to fig3 a and 3 b , meter 10 includes volumetric meter roller 100 which may be geared to the wheels of the air seeder trailer or , if carried on a separate product dispensing cart , to the wheels of the cart , and can be set to dispense a fixed volume of product per unit of linear distance traveled by the air seeder . in the embodiment shown in fig3 a and 3 b , meter 10 comprises volumetric meter roller 100 having an axial bore therethrough . meter drive shaft 108 , having roller sprocket 109 at one end , is inserted into the axial bore and when meter roller 100 is inserted through aperture 110 and mounted at the bottom of hopper 140 , roller sprocket 109 meshes with agitator sprocket 112 . agitator sprocket 112 is attached to the end of agitator shaft 114 and in this embodiment is geared to the wheels of either the air seeder trailer or product dispensing cart ( not shown ). meter 10 further comprises meter rotation sensor 120 which actually senses the number of rotations of the meter drive shaft 108 by sensing sensor sprocket 111 , which is attached to shaft 108 , and hence senses the number of rotations of meter roller 100 . meter 10 may also comprise a means for rotating the meter drive shaft 108 such as a crank or handle ( not shown ) which can be used to manually turn the meter drive shaft 108 to dispense a unit of product from the hopper for collection in a container such as a pan or bag ( generally located below the meter roller ) so that the unit of product can be weighed in order for the operator to ultimately calibrate the number of rotations needed to dispense x lbs ( or kg ) of product per acre ( or hectare ) of land to be seeded . fig4 and 5 are overviews of another embodiment of the invention . a tractor 121 is shown towing a tool bar 123 , which may comprise a plurality of ground openers ( not shown ), collectively referred to as a seeder . towed behind the tool bar 123 is an air cart 125 for providing at least one product , such as seed and / or fertilizer , to the tool bar 123 . the air cart 125 has a metering system having at least one meter , such as the metering system shown in fig3 a . a calibration console 122 is provided comprising an input pad 131 and a screen 133 . the calibration console 122 is provided in a first position at or near the air cart 125 and the metering system . the calibration console 122 can be used to calibrate the metering system , setting the feed rate and / or dispensing rate of the product , at or near the metering system where the calibration console 122 is positioned . a monitoring console 140 having a display 140 can also be provided at a second position at or near the tractor 121 and in one embodiment , the monitoring console 140 can be provided in a cab of the tractor 121 . the monitoring console 140 can allow a user operating the tractor 121 to monitor the feed rate and / or dispensing rate of the product ; typically by displaying the feed rate and / or dispensing rate of the product on the display 142 of the monitoring console 140 . the monitoring console 140 can also allow the operator to control a number of other functions related to the monitoring and / or control of the seeder . in a further embodiment , the monitoring console 140 can allow an operator to adjust the feed rate and / or dispensing rate of the product from the cab of the tractor 121 , even while the seeder is in use dispending product . in one embodiment , the monitoring console 140 may have all the functionality of the calibration console 122 and in addition , provide a number of additional functions related to monitoring and / or controlling the operation of an air seeder . in another embodiment , the monitoring console 140 may not have the functionality of the calibration console 122 , requiring the user to calibrate the metering system using the calibration console 122 , but can allow the user to monitor and / or control the rest of the operation of the air seeder using the monitoring console 140 . in one embodiment , the calibration console 122 could act as an interface to the monitoring console 140 . the calibration of the metering system could be performed on the monitoring console 140 using the calibration console 122 as a remote connection to the calibration console 122 , but utilizing the processing capabilities of the monitoring console 140 to perform the necessary processes and calculations . this can allow the processing requirements of the calibration console 122 to be greatly reduced . the calibration console 122 can be electrically connected at the first position to an electrical harness 124 , which may comprise a tractor harness 126 , a toolbar harness 130 and an air cart harness 134 . the monitoring console 140 can also be electrically connected to the electrical harness 124 at the second position . in this manner , the metering system of the air cart 125 can be calibrated using the calibration console 122 located at or near the metering system and then the operation of the seeder can be monitored and / or controlled during use by an operator from the cab of the tractor 121 using the monitoring console 140 . this allows different devices to be used for the calibration console 122 and the monitoring console 140 . in one embodiment , the monitoring console 140 with its additional functionality to monitor and / or control the operation of the air seeder may be a more complex and / or expensive device than the calibration console 122 , while the calibration console 122 with its more limited functional requirements can be a simpler and / or less expensive device . the previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention . various modifications to those embodiments will be readily apparent to those skilled in the art , and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention . thus , the present invention is not intended to be limited to the embodiments shown herein , but is to be accorded the full scope consistent with the claims , wherein reference to an element in the singular , such as by use of the article “ a ” or “ an ” is not intended to mean “ one and only one ” unless specifically so stated , but rather “ one or more ”. all structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims . moreover , nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims . no claim element is to be construed under the provisions of 35 usc 112 , sixth paragraph , unless the element is expressly recited using the phrase “ means for ” or “ step for ”.
a calibration device for calibrating a metering system that dispenses a product to a seeder towed by a farm vehicle is provided for obtaining and maintaining a desired rate of delivery of the product from the seeder . the calibration device includes a first console port positioned at or near the farm vehicle and a second console port at or near the metering system , each operative to receive at least one a calibration console for calibrating the rate of product delivery and adjust the metering system accordingly .