The term “standard Babcock testing glassware” applies to glassware and weights complying with the following specifications:
(1)Standard milk test bottles. —
Graduation. — The total per centum graduation shall be 8. The graduated portion of the neck shall have a length of not less than 63.5 millimeters (2 ½ inches). The graduation shall represent whole percent, .5 percent, and tenths percent. The tenths percent graduation shall not be less than 3 millimeters in length; the .5 percent graduations shall be 1 millimeter longer than the tenths percent graduation, projecting 1 millimeter to the left. The whole percent graduations shall extend at least one-half way around the neck to the right and projecting 2 millimeters to the left of the tenths percent graduations. Each percent graduation shall be numbered, the number being placed on the left of the scale. The error at any point of the scale shall not exceed .1 percent.
Neck. — The neck shall be cylindrical, and the cylindrical shape shall extend for at least 9 millimeters below the lowest and above the highest graduation mark. The top of the neck shall be flared to a diameter of not less than 10 millimeters.
Bulb. — The capacity of the bulb up to the junction of the neck shall not be less than 45 cubic centimeters. The shape of the bulb may be either cylindrical, or conical with the smallest diameter at the bottom. If cylindrical, the outside diameter shall be between 34 and 36 millimeters; if conical, the outside diameter of the base shall be between 31 and 33 millimeters and the maximum diameter between 35 and 37 millimeters.
Charge. — The charge of the bottle shall be 18 grams.
Height. — The total height of the bottle shall be between 150 and 165 millimeters (5 ⅞ and 6 ½ inches).
(2)Standard cream test bottles. —
Three types of bottles shall be accepted as standard cream test bottles; a 50 percent, 9 gram, short-neck bottle; a 50 percent, 9 gram, long-neck bottle; and a 50 percent, 18 gram, long-neck bottle.
Fifty percent, 9 gram, short-neck bottles:
Graduation. — The total percent graduation shall be 50. The graduated portion of the neck shall have a length of not less than 63.5 millimeters (2 ½ inches). The graduation shall represent 5 percent, 1 percent, and .5 percent. The 5 percent graduation shall extend at least half way around the neck to the right. The .5 percent graduation shall be at least 3 millimeters in length, and the 1 percent graduation shall have a length intermediate between the 5 percent and the .5 percent graduations. Each 5 percent graduation shall be numbered, the number being placed on the left of the scale. The error at any point of the scale shall not exceed .5 percent.
Neck. — The neck shall be cylindrical, and the cylindrical shape shall extend at least 9 millimeters below the lowest, and 9 millimeters above the highest graduation mark. The top of the neck shall be flared to a diameter of not less than 10 millimeters.
Bulb. — The capacity of the bulb up to the junction of the neck shall not be less than 45 cubic centimeters. The shape of the bulb may be either cylindrical, or conical, with the smallest diameter at the bottom. If cylindrical, the outside diameter shall be between 34 and 36 millimeters; if conical, the outside diameter of the base shall be between 31 and 33 millimeters, and the maximum diameter between 35 and 37 millimeters.
Charge. — The charge of the bottle shall be 9 grams. All bottles shall bear on top of the neck, above the graduations, in plainly legible characters, a mark defining the weight of the charge to be used (9 grams).
Height. — The total height of the bottle shall be between 150 and 165 millimeters (5 ⅞ and 6 ½ inches), which is the same as standard milk test bottles.
Fifty percent, 9 grams, long-neck bottles:
The same specifications in every detail as specified for the 50 percent, 9 grams, short-neck bottle, shall apply for the long-neck bottle, with the exception, however, that the total height of this bottle shall be between 210 and 235 millimeters (8 ¼ and 8 ⅞ inches), and that the total length of the graduation shall not be less than 120 millimeters.
Fifty percent, 18 grams, long-neck bottles:
The same specifications in every detail as specified for the 50 percent, 9 grams, long-neck bottles, except that the charge of the bottle shall be 18 grams. All bottles shall bear, on the top of the neck, above the graduation, in plainly legible characters, a mark defining the weight of the charge to be used (18 grams).
(3)The standard Babcock pipette. —
Total length of pipette, not more than 330 millimeters (13 ¼ inches). Outside diameter of suction tube, 6 to 8 millimeters.
Length of suction tube, 130 millimeters. Outside diameter of delivery tube, 4.5 to 5.5 millimeters. Length of delivery tube, 100 to 120 millimeters. Distance of graduation mark above bulb, 30 to 60 millimeters. Nozzle, straight. Delivery, 17.6 cubic centimeters of water at 20° Centigrade in 5 to 8 seconds.
(4)Standard weights. —
The standard weights shall be of 9 grams and 18 grams denominations.