PART 4. GENERAL INFORMATION XXXIV. STANDARD SAMPLES 1. SUCROSE 44 This Bureau is prepared to issue standard sucrose samples (see p. 392) prepared by recrystallization from aqueous solution or by precipitation with alcohol. For each sample, the process of purification has been continued until analysis shows a satisfactory product. A certificate of analysis accompanies the sample. The sugar usually contains but little moisture, and in a moderately dry atmosphere shows very little hygroscopicity. It is advisable to store the sample in a cool, dry place. If placed in a desiccator, the drying agent used should be pure. Vapors from impure sulfuric acid or phosphorus pentoxide frequently damage the sugar. The uses of standard sucrose samples may be stated briefly as follows: (1) As a primary saccharimetric standard; (2) as a source of pure invert sugar for the standardization of analytical determinations of reducing sugar; (3) as a standard for the calibration of viscometers; and (4) as a material for standardization of bomb calorimeters. Sucrose has the advantage of being nonvolatile and nonhygroscopic. It is rather difficult to ignite and sometimes does not burn completely. It has a heat of combustion of about 3,950 calories, or only about half that of coal. The more exact value for each sample will be given in the certificate. For details of the standardization of bomb calorimeters, see NBS Circular C11. 2. DEXTROSE 45 The standard dextrose samples are prepared by purification of the purest glucose of commerce in the manner described on page 390. A certificate of analysis will show the degree of purification of the sample. The standard dextrose sample is intended to assist in research work of a general nature and, in particular, to serve as a standard reducing sugar for analytical work. XXXV. TESTS 1. SPECIAL The special requirements of scientific investigators, manufacturers of apparatus, and others, for higher precision than is considered in the following schedules, will be met as far as the regular work of the Bureau will permit. The application for a special test should state fully the purpose for which the apparatus has been used or is to be used in the future, the need for the test, and the precision desired. The test should be arranged for by correspondence before shipment of the apparatus. The special fee charged will depend chiefly upon the time consumed and the amount of alteration required in the regular Bureau testing set-ups. An estimate will be given when possible. 44. 45 See list on p. 559. 2. GENERAL INSTRUCTIONS TO APPLICANTS FOR TESTS (a) APPLICATION FOR TEST The request for test should be made in writing, addressed to the National Bureau of Standards, Washington, D. C., and should enumerate the articles submitted for test, giving the identification marks of each-for example, maker's name and number-and should state the nature of the test desired. (b) NATURE OF TEST The classification of tests in this Circular should be followed, and the schedule numbers should be used to indicate the test desired. When the desired test is not included under the regular schedules, the applicant must comply with the requirements for special tests. When apparatus is sent simply for test, without definite instructions, the Bureau will, if practicable, decide upon the nature of the test. (c) IDENTIFICATION MARKS All packages should bear the shipper's name and address and, when convenient, a list of the contents. Each separate piece of apparatus or sample of material should be provided with an identification mark, which in many cases may be the maker's name and number. The identification mark should be given in the application for the test. (d) SHIPPING DIRECTIONS Apparatus or test specimens should be securely packed in cases or packages which will not be broken in transportation. The shipment in both directions is at the applicant's risk. To facilitate packing and shipping, the tops of the cases should have the return or forwarding address on the underside and should be put on with screws. Transportation charges are payable by the party desiring the test and must be prepaid. Unless otherwise arranged, articles will be returned or forwarded by express collect. (e) RETURN OF APPARATUS Regular tests will be made in the order in which the applications are received, except as this practice may be varied by grouping similar tests together. It is suggested, therefore, that the applicant, if possible, make request for a test from 2 weeks to 2 months preceding the shipment of the apparatus. This facilitates the work of the Bureau as well as the prompt return of the apparatus. (f) ADDRESS Apparatus submitted for test, as well as all correspondence, should be addressed to the National Bureau of Standards, Washington, D. C. Apparatus delivered in person or by messenger should be accompanied by a written request for the test. (g) REMITTANCES Fees should be sent with the request for test, in accordance with the following schedules, or promptly upon receipt of bill. Certificates are not given nor is apparatus returned until the fees due thereon have been received. Remittances may be made by money order or check drawn to the order of the National Bureau of Standards. 3. CERTIFICATES AND STATEMENTS Apparatus that fulfills the requirements for certification will be tested and given a certificate of corrections. The certificate can only indicate the corrections of the apparatus at the time of the test and does not guarantee the constancy of the values. When there are defects which exclude an apparatus from certification, a report will be issued instead of a certificate, in which such information as has been found will be stated. 4. TEST-FEE SCHEDULES 46 Effective July 1, 1940, superseding all previous schedules for the items covered. TEST FEE SCHEDULE 421.-Polariscopes for absolute measurement Circular scales Fee 421a Polariscopes for absolute measurement: Determination of true value of five to ten points ±0.01°, $7.50 421c Determination of true value of five to ten points ±0.002°, 12.50 2.00 TEST FEE SCHEDULE 422.-Elliptic analyzers and physical properties of glass Item 422a Glass: Description Fee 422b Determining the softening points and annealing ranges up Determining deformability up to 700° C and over a range $25.00 60. 00 TEST FEE SCHEDULE 423.-Quartz control plates and polariscope cover glasses Items Description Fee Quartz control plates: 423a Certification of rotation in circular degrees, "yellow-green $3.00 423b Certification of same in circular degrees and sugar degrees 4.00 423c Certification of rotation at other temperatures by special 423d 423e Test of quartz control plates rejected, each (see 423y)--- Cover glasses: 423f Absence of double refraction, each (see 423y). 423y Minimum total charge billed for any test_ 25 2. 00 . 10 2.00 "For special tests not covered by these schedules, fees will be charged dependent on the nature of the test. Copies of certificates or reports previously issued or reissue of worn or damaged certificates or reports returned, each 25 cents; minimum fee, $1.00. 424d 424e Adjustment and certification at five points.. Certification at five points on positive wedge and three points on negative wedge.. Certification at five points on each wedge. Adjustment and certification at five points for each wedge_ Fee $6.50 12.50 to 35.00 9.00 10. 00 15. 00 to 35.00 7.50 425z Item Molasses: Determination of specific gravity or weight per gallon Determination of purity of purified sucrose, dextrose, and TEST FEE SCHEDULE 311 (EXTRACT).—Laboratory thermometers Description Thermometers, testing at points in the interval 0° to 100° C Thermometers, testing at points in the interval 0° to 35° C Fee Items (a) to (d), inclusive, apply particularly to the types 311e 311f Calorimetric thermometers, testing at intervals of 2° C or 5° F 5.00 6.00 TEST FEE SCHEDULE 311 (EXTRACT).—Laboratory thermometers—Continued Item Description Fee 311ff Beckmann thermometers, calibration by means of mercury Unless the request for test of a Beckmann thermometer speci- Thermocouples for temperatures between -40° and 500° C Thermocouples for range 40° to 500° C, calibration per $12.00 10. 00 311j 311k 3.00 Items (j) and (k) do not cover tests of multiple junction as- Items (g) to (k), inclusive, refer to tests described in National 311m When instruments submitted are found by preliminary tests to be unsuitable for test, a charge will be made to cover the cost of the preliminary work. Minimum fee. 311y Minimum fee on any test or transaction... – Item TEST FEE SCHEDULE 297.-Polariscope Tubes 297c Polariscope tubes— Description Determination of the average length of a polariscope ob- 1.00 1.00 Fee $1.00 (2) 200-mm tubes, each 1.00 (3) 400-mm tubes, each 2.00 297d Same, when four or more of the same size are submitted at Determination of average length of 100 and 200 mm polar- (1) 100-mm tubes, each.... (2) 200-mm tubes, each 297f Same, when four or more of the same size are submitted at the same time: 1.50 2.00 (1) 100-mm tubes, each (2) 200 mm tubes, each 1. 15 1.50 297g Polariscope tubes Determination of average length of 400 mm polariscope 3.00 297h Same, when four or more are submitted at the same time, 2.25 297y Minimum total charge billed for any test.. 2.00 |