9 CFR § 201.73-1 - Instructions for weighing livestock.
Stockyard operators, market agencies, dealers, and packers who operate scales on which livestock is weighed in purchase or sales transactions are responsible for the accurate weighing of such livestock. They shall supply copies of the instructions in this section to all persons who perform weighing operations for them and direct such person to familiarize themselves with the instructions and to comply with them at all times. This section shall also apply to any additional weighers who are employed at any time. Weighers must acknowledge their receipt of these instructions and agree to comply with them, by signing in duplicate, Form PSD 4000 provided by the Packers and Stockyards Division. One copy of the form is to be filed with a regional office of the Packers and Stockyards Division and the other retained by the agency employing the weighers.
(a) Balancing the empty scale.
(1) The empty scale shall be balanced each day before weighing begins, and maintained in correct balance which weighing operations continue. The zero balance shall be verified at intervals of not more than 15 drafts or 15 minutes, whichever is completed first. In addition, the zero balance of the scale shall be verified whenever a weigher resumes weighing duties after an absence from the scale and also whenever a load exceeding half the scale capacity or 10,000 pounds (whichever is less) has been weighed and is followed by a load of less than 1,000 pounds, verification to occur before the weighing of the load of less than 1,000 pounds.
(2) The time at which the empty scale is balanced or its zero balance verified shall be recorded on scale tickets or other permanent records. Balance tickets must be filed with other scale tickets issued on that date.
(3) Before balancing the empty scale, the weigher shall assure himself that the scale gates are closed and that no persons or animals are on the scale platform or in contact with the stock rack, gates, or platform. If the scale is balanced with persons on the scale platform, the zero balance shall be verified whenever there is a change in such persons. When the scale is properly balanced and ready for weighing, the weigher shall so indicate by an appropriate signal.
(4) Weighbeam scales shall be balanced by first seating each poise securely in its zero notch and then moving the balance ball to such position that a correct zero balance is obtained. A scale equipped with a balance indicator is correctly balanced when the pointer comes to rest at zero. A scale not equipped with a balance indicator is correctly balanced if the weighbeam, when released at the top or bottom of the trig loop, swings freely in the trig loop in such manner that it will come to rest at the center of the trig loop.
(5) Dial scales shall be balanced by releasing all drop weights and operating the balance ball or other balancing device to obtain a correct zero balance. The indicator must visually indicate zero on the dial and the ticket printer must record a correct zero balance.
(6) Electronic digital scales should be properly warmed up before use. In most cases, it is advisable to leave the electric power on continuously. The zero load balance shall be verified by recording the zero balance on a scale ticket. The main indicating element and the remote visual weight display shall indicate zero when the balance is verified. The proper procedure for balancing this type of scale will vary according to the manufacturer. Refer to the operator's manual for specific instructions.
(b) Weighing the load.
(1) Before weighing a draft of livestock, the weigher shall assure himself that the entire draft is on the scale platform with the gates closed and that no persons or animals off the scale are in contact with the platform, gates, or stock rack.
(i) On a weighbeam scale with a balance indicator, the weight of a draft shall be determined by seating the poises at such positions that the pointer will come to rest within the central target area or within 1/4 (0.25) inch of the zero mark.
(ii) On a weighbeam scale without a balance indicator, the weight shall be determined by seating the poises at such positions that the weighbeam, when released from the top or bottom of the trig loop, will swing freely and come to rest at the approximate center of the trig loop.
(iii) On a dial scale, the weight is indicated automatically when the indicator moves around the dial face and comes to rest.
(iv) On an electronic digital scale, the weight of a draft is indicated automatically when the weight value indicated stabilized.
(2) The correct weight of a livestock draft is the value in pounds indicated when a correct load balance is obtained. The weigher should always concentrate his attention upon the beam tip, balance indicator or dial indicator while weighing and not concern himself with reading the visible weight indications until correct load balance is obtained. On electronic digital scales, the weigher should concentrate on the pulsing or flickering of weight values to assure that the unit indicates a stable weight before activating the print button.
(c) Recording the weight.
(1) The weight of each draft shall be recorded immediately after the load balance is obtained and before any poises are moved or the load is removed from the scale platform. The weigher shall make certain that the printed weight record agrees with the weight value visually indicated when correct load balance is obtained. He shall also assure himself that the printed weight value is distinct and legible.
(2) The weight printing device on a scale shall be operated only to produce a printed or impressed record of the weight value while the livestock load is on the scale and correctly balanced. If the weight value is not printed clearly and correctly, the ticket shall be marked void and a new one printed before the livestock is removed from the scale.
(d) Scale tickets.
(1) Scale tickets used to record the weight values of livestock in purchase or sales transactions shall be used, at any given scale, in the order of their consecutive serial numbers unless otherwise marked to show the order of their use. All tickets shall show the date of the weighing and the name or initials of the weigher performing the weighing service.
(2) No scale tickets shall be destroyed or otherwise disposed of because they are soiled, damaged, incorrectly executed, or voided. They shall be preserved and filed to comprise a complete serial number sequence.
(3) No scale ticket shall be used to record the weight of a livestock draft for “catch-weight,” inventory, transportation charge or other nonsale purposes unless the ticket is clearly marked to show why the weight was determined.
(4) When weight values are recorded by means of automatic recording equipment directly on the accounts of sale or other basic records, such record may serve in lieu of a scale ticket.
(e) Weigher's responsibilities.
(1) The primary responsibility of a weigher is to determine and accurately record the weight of livestock drafts without prejudice or favor to any person or agency and without regard for livestock ownership, price, condition, fill, shrink, or other considerations. A weigher shall not permit the representations or attitudes of any persons or agencies to influence his judgment or action in performing his duties.
(2) Unused scale tickets, or those which are partially executed but without a printed weight value, shall not be left exposed or accessible to unauthorized personnel. All such tickets shall be kept under lock when the weigher is not at his duty station.
(3) Accurate weighing and correct weight recording require that a weigher shall not permit his operations to be hurried to the extent that inaccurate weights or incorrect weight records may result. Each draft of livestock must be weighed accurately to the nearest minimum weight value that can be indicated or recorded. Manual operations connected with balancing, weighing, and recording shall be performed with the care necessary to prevent damage to the accurately machined and adjusted parts of weighbeams, poises, and printing devices.
(4) Livestock owners, buyers, or others having legitimate interest in a livestock draft must be permitted to observe the balancing, weighing, and recording procedures, and a weigher shall not deny them that right or withhold from them any information pertaining to the weight of that draft. He shall check the zero balance of the scale or reweigh a draft of livestock when requested by such parties.
(f) Sensitivity control.
(1) A scale must be sensitive in response to platform loading if it is to yield accurate weights. It, therefore, is the duty of a weigher to assure himself that interferences, weighbeam friction, or other factors do not impair sensitivity. He should satisfy himself, at least twice each day, that the scale is sufficiently sensitive, and if the following requirements are not met, he should report the facts to his superior or employer immediately.
(2) A weighbeam scale with a balance indicator is sufficiently sensitive if, when the scale is balanced with the pointer at the center of the target, movement of the fractional poise one graduation will change the indicator rest point 1/4 inch (0.25) or the width of the central target area, whichever is greater.
(3) A weighbeam scale without a balance indicator is sufficiently sensitive if, when the scale is balanced with the weighbeam at the center of the trig loop, movement of the fractional poise two graduations will cause the weighbeam to come to rest at the bottom of the trig loop.
(4) Adjustable damping devices are incorporated in balance indicators and in dial scales to absorb the effects of load impact and assist in bringing the indicator to rest. The weigher should be familiar with the location and adjustment of these damping devices and should keep them adjusted so that the pointer will oscillate freely through at least one complete cycle of movement before coming to rest at its original position.
(5) Friction at weighbeam bearings may reduce the sensitivity of the scale, cause sluggish weighbeam action and affect weighing accuracy. A weigher should inspect the weighbeam assembly daily to make certain that there is clearance between the weighbeam and the pivot bearings.
(6) Interferences or binding of the scale platform, stock rack, gates or other “live” parts of the scale are common causes of weighing inaccuracy. A weigher should satisfy himself, at the beginning of each weighing period, that all such “live” parts have sufficient clearance to prevent interferences.
(g) General precautions.
(1) The poises of weighbeam scales are carefully adjusted and sealed to a definite weight at the factory and any change in that weight seriously affects weighing accuracy. A weigher, therefore, should be certain that poise parts do not become broken, loose or lost and that no material is added to a poise. Balancing or weighing shall not be performed while a scale ticket is in the slot of a weighbeam poise.
(2) Stops are provided on scale weighbeams to prevent movement of poises back of the zero graduation when balancing or weighing. When the stops become worn or broken and allow a poise to be set behind the zero position, this condition should be reported and corrected without delay.
(3) Foreign objects or loose material in the form of nuts, bolts, washers or other material on any part of the weighbeam assembly, including the counter-balance hanger or counter-balance weights, are potential sources of weighing error. Loose balancing material must be enclosed in the shot cup of the counter-balance hanger, and counter-balance weights must not be of the slotted type which can readily be removed.
(4) Whenever for any reason a weigher has reason to believe that a scale is not functioning properly or not yielding correct weight values, he shall discontinue weighing, report the facts to the parties responsible for scale maintenance, and request inspection, test, or repair of the scale.
(5) When a scale has been adjusted, modified, or repaired in any manner which may affect the accuracy of weighing or weight recording, the weigher shall not use the scale until it has been tested and inspected and found to be accurate.
(6) Count-off men, gate men, or others assigned to open or close scale gates or to drive livestock on or off the scale, shall perform those functions as directed by the weigher's signals or spoken instructions. They shall prevent persons or animals off the scale from being in contact with any part of the scale platform, stock rack, or gates while the scale is being balanced or used for weighing. They shall not open gates or remove livestock from the scale until directed by the weigher.