1. A nuclear magnetic resonance instrument installed on a hay baler used to measure the moisture content of the fodder prior to the bale leaving the baler.
2. A nuclear magnetic resonance instrument installed on a cotton baler to measure the
moisture content of the cotton prior to the bale leaving the baler.
3. An apparatus as in claim 1 wherein said instrument is adapted to measure the bulk density of the bale.
4. An apparatus as in claim 2 wherein said instrument is adapted to measure the bulk density of the bale
5. An apparatus as in claim I wherein the iastrument measures the nutritional properties of the fodder.
6. An apparatus as in claim 2 wherein the instrument measures the oil content of the cotton seed.
FIELD OF THE INVENTION
 The present invention relates to an apparatus for physical analysis of hay or cotton bales. It can be used to measure the nutritional value of fodder, in particular hay bales. It can also be used to measure other properties of cotton bales such as the moisture or oil content.
BACKGROUND OF THE INVENTION
 The true commercial value of bales of fodder, both hay and silage, is the nutritional value of the fodder. Other factors such as moisture and microbial activity are also important, but more for the safety and spoiling aspects of the fodder such as spontaneous combustion and maintaining the nutritional value of the fodder in storage.
 Moisture in seed cotton and cotton lint is an important parameter in the processing and storage of cotton. Moisture is also important in seed cotton because above certain moisture contents the germination rates of the cotton seed used for future crops may be compromised. Also, the oil content of the seed is another important commercial parameter.
 Currently electromagnetic methods (typically in the form of microwaves) are used to measure the physical properties (typically moisture content) of fodder. However this method is not capable of determining the quantities of any particular chemical compounds which may lead to the determination of the nutritional value of the fodder.
 Traditionally one of the main parameters which sellers and buyers have based the co mmercial value of hay on has been a mathematical combination of values obtained from laboratory assays of samples taken from the hay commonly referred to as the "Relative Feed Value" (RFV) or "Relative Feed Quality" (RFQ). Animal nutrition experts normally require more information about the chemical analysis of the hay than just the value of RFV or RFQ to determine the appropriate feed rations for their client's livestock.
 The One-sided Access Nuclear Magnetic resonance (OSA-NMR) technique has been used in a number of scientific research (e.g. ice cores in the Antarctic) and industrial application such as for motor vehicle tyres and wooden panel board manufacturing plants.
 There appears to be no current knowledge, information or experience that directly relates to this application of OSA-NMR. The only techniques currently in use are microwave and conductivity methods to determine total moisture in bulk materials. Neither of these methods differentiate between "sap" moisture (stem moisture) and "dew" moisture (free moisture) which determines how 'cured" the hay is which is ultimately the main factor in preventing spontaneous combustion
 This invention is the application of an apparatus and method to determine some of the physical properties of fodder such as moisture and nutritional properties. The same invention can be also be used to determine some of the physical properties of seed cotton and cotton lint such as moisture and oil content.
SUMMARY OF THE INVENTION
 Therefore in one form of the invention there is proposed a nuclear magnetic resonance instrument adapted to be installed on a hay baler and positioned so that it makes contact with the bale as it exits the baler and measures various properties of the bale that are then used to determine the nutritional value of the fodder prior to the bale leaving the baler.
 In a further form of the invention there is proposed a hay baler including a nuclear magnetic resonance instrument adapted to be installed on the hay baler and positioned so that it makes contact with the bale as it exits the baler and measures various properties of the bale that are then used to determine the nutritional value of the fodder prior to the bale leaving the baler
[0011 ] In preference the baler further includes an apparatus to measure the moisture content of the bale.
 In preference both the nutritional value of the fodder and the moisture content are recorded on an RFID lag that is attached to each bale.
BRIEF DESCRIPTION OF THE DRAWINGS
 Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows.
 Figure 1 is a schematic diagram of a NMR sensor and the magnetic field density;
 Figure 2 illustrates in perspective exploded view the sensor; and
 Figure 3 illustrates the sensor when assembled.
DETAILED DESCRIPTION OF THE INVENTION
 Turning now to the drawings in detail they illustrate a NMR sensor 10 having two magnets 12 supported on yoke 14. A radio frequent coil 16 between the magnets produces the NMR excitation field 18.
 In both fodder and cotton applications this invention can determine the different types of moisture in the bulk material. These types of moisture are typically referred to as sap moisture and free (or dew) moisture in fodder, or bound and tree moisture in picked cotton.
 The advent of one sided nuclear magnetic resonance (NMR) techniques has enabled the NMR technology to be used in a mobile environment.
 Modern hay making processes are carried out using what is commonly termed ''precision farming" techniques. This includes the use of Global Positioning Systems (GPS) to determine the location of the baling machine at any particular time. Combining the near real time measurement of the moisture contents and nutritional value of the fodder by NMR on the hay baler and the GPS location information of where each bale is made creates a data base of moisture and nutritional value for each bale or lot of bales. Typically this data base would be uploaded to the Internet. In most cases the uploading process could be part of existing data management systems already in use by leading tractor manufacturers. This process makes it possible to determine the commercial value of the fodder from a data base immediately without having to take samples and have them analysed with a laboratory instrument.
[0021 ] In a similar way the picking and processing cotton can benefit from this application of this invention. In this case it is primarily the moisture content which is of interest and may be included in a data base. Such a data base is of benefit to the processing plants from a payment and a processing aspect.
 Since the advent of die one sided nuclear magnetic resonance instrument , those who are skilled in the art of using nuclear magnetic resonance instruments have typically been applying such instrument in the laboratory and in field surveys for scientific purposes.
 Tills invention takes the use of one sided nuclear magnetic resonance instruments into the realm of on line near real time analysis of an agricultural bulk commodity. In this case the bulk commodity being analysed may be in the form of bales of hay, silage, cotton bales, cotton modules, and on line in hay processing plants or cotton gins.
 The instrument may be mounted hay balers, cotton pickers or installed in hay processing plants of cotton gins.
 Typically the one sided nuclear magnetic resonance instrument will measure the bonding properties of the protons in the Hydrogen atoms in the sample being presented. With advances in techniques which exist in traditional nuclear magnetic resonance machines being applied to the one sided nuclear magnetic resonance other atoms may be examined such as, Carbon and Nitrogen and determines mere physical properties of the bulk material being presented to the instrument
 In the hay or silage application a single sided nuclear magnetic resonance instrument is mounted either to one of the baler doors, or to the baler frame in a manner which provides a firm stable contact with the bale as it moves through or exits the bale chamber. Balers are well known and it is not the intention to discuss them in any detail. Suffice to say is (hat the NMR instrument is positioned so that it makes contact with the bale as it exits the baler. Il can be located on any surface area of the baler, but typically for easy access it is located to the side of the bale.
 An alternative and preferred way to install the instrument is to build the instrument into one of the bale chamber doors. This will ensure good contact with the bale and intrinsic protection for extraneous material adhering to the (ace of the instrument.
 If the instrument is mounted on the baler frame it will require a mechanism to press the face of the instrument against the fodder bale.
 Typically the electronics which controls the electric field and measures the resonance aspects of the atoms will also provide the process control aspects and communications with the hay baler electronics. The communications typically includes an ISO11783 interface to the hay baler which provides the instrument with the status of the baler and is also one of the possible mechanisms for the instrument to send the nutritional information to the baler electronics system.
 The instrument that is the subject of this preferred embodiment may also be used as a separate hand held device, however, such an application is not the subject of this patent.
[0031 ] In another embodiment of the invention the single skied nuclear magnetic resonance instrument is mounted on a cotton picker /baler either internally or on the rear handler in a mechanism which provides a firm stable contact with the bale on the handler.
 Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in this field.  In the present specification and claims (if any), the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers.