1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2014 SAE InternationalAll rights reserved. No part of this publi
3、cation may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AS9968AEROSPACESTANDARDAS9968Issued 2014-07Laboratory Viscosity Measurement of Thickened Airc
5、raftDeicing/Anti-icing Fluids with the Brookfield LV ViscometerRATIONALERenamed the document from AIR to AS since it is meant to be used as a standard and has been used as such over the past 10 years, so AS seems more appropriate to reflect this.Added “Laboratory” and “the Brookfiled viscometer” to
6、the title to distinguish the document better from the AIR5704 (field viscosity test for thickened aircraft anti-icing fluids).Text cleaned-up in whole document to make it more clear and better readable.Deleted the reference to AS5485 as this document is not referenced in the text and has no relation
7、 to this AS9968 document.Deleted the reference to ASTM D2196 as this AS9968 deviates from the D2196 document with specific requirements. Further, the reference was only to a small part of the D2196 document anyhow, which is replaced by referring to the instrument manufacturers instructions taking aw
8、ay the need for keeping track of changes to the D2196 document.The role of alternate viscosity measurement methods established by fluid manufacturers is provided in the scope. Thisrole is specified in the Transport Canada and FAA Holdover Time Guidelines.Some items in 3.3 (Requirements) have been mo
9、ved to get a more logic order of items.A method for removing air bubbles from fluid samples has been added.The UL Adaptor (including corresponding spindle) is added for measurements of very low viscosities for accuracy reasons.A specific measurement container (600 mL low form beaker) is added for us
10、e with spindles LV1 and LV2 disc. This has been done as Brookfield states that beaker size/form can have an impact on viscosity measurement (narrower/smaller container = higher viscosity reading). Words have been added to emphasize that in order to compare results of two viscosity measurements, the
11、measurements MUST be conducted using the exact same method, including spindle and measurement container. This is made clearer by separating spindle selection into that for original/baseline (for fluid manufacturers) and comparative (for fluid users) measurements.More detailed information is provided
12、 for spindle selection in the range of 10 000 to 20 000 mPa.s.SAE INTERNATIONAL AS9968 Page 2 of 5FOREWORDIn freezing weather conditions, situations conducive to aircraft icing on the ground may be encountered. Under these conditions, thickened anti-icing fluids (AMS1428) are applied (using applicat
13、ion methods described in ARP4737) to protect aircraft surfaces.Aircraft operators and deicing companies perform viscosity checks on these thickened anti-icing fluids for quality control purposes. Since checks are performed by various companies, a standard viscosity measurement method has been select
14、ed to allow comparison of results. This Aerospace Standard (AS) describes the selected method.1. SCOPEThis AS describes a standard method for viscosity measurements of thickened (AMS1428) anti-icing fluids. Fluid manufacturers may publish alternate methods for their fluids. In case of conflicting re
15、sults between the two methods, the manufacturer method takes precedence.To compare viscosities, exactly the same measurement elements (including spindle and container size) must have been used to obtain those viscosities.1.1 PurposeTo provide a standard method for viscosity measurements. This method
16、 is intended to be used for field verification and auditing purposes to compare viscosities of different samples and to compare sample viscosities to limits published for aerodynamic acceptance and holdover time use.2. REFERENCES2.1 Applicable DocumentsThe following publications form a part of this
17、document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In theevent of conflict between the text of this document and references cited herein, the text of thi
18、s document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.2.1.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada
19、) or 724-776-4970 (outside USA), www.sae.org.AMS1428 Fluid, Aircraft Deicing/Anti-Icing, Non-Newtonian (Pseudoplastic), SAE Types II, III, and IVARP4737 Aircraft Deicing/Anti-icing Methods2.2 AbbreviationsLOWV: Lowest On Wing ViscositymPa.s: milli Pascal.secondsSAE INTERNATIONAL AS9968 Page 3 of 53.
20、 MEASUREMENT METHOD3.1 InstrumentA calibrated Brookfield LV series viscometer shall be used.NOTE: RV, HA, or HB series Brookfield viscometers shall not be used for this measurement. It may be necessary to verify on the label on the back of the instrument if it is an LV series model, because normally
21、 the display on the front only indicates the sub model.3.2 Basic MethodViscosity is determined by measuring the torque on a spindle rotating at a constant speed in a fluid.To carry out a measurement, follow the instrument manufacturers instructions, while taking into account the requirements listed
22、in 3.3.3.3 Requirements3.3.1 Fluid ShearingThe fluid may be degraded by shearing; therefore, the fluid processing shall avoid excessive shaking/stirring and inappropriate methods of filling the measurement container.3.3.2 Air BubblesThe fluid shall be substantially free of air bubbles. Air bubbles c
23、an be removed by centrifuging the fluid at 3000 rpm. To avoid fluid stratification (layers), it is important that the fluid is centrifuged only for a short time (5 to 10 minutes is typically appropriate).3.3.3 Fluid ConditionThe fluid shall be homogeneous (no lumps or stratification) before filling
24、the sample container.3.3.4 Fluid TemperatureThe viscosity reading shall be taken at a fluid temperature of 20 C 1 C. 3.3.5 Measurement Containerx For spindles LV1 and LV2 disc, the measurement container size/form shall be a 600 mL low form beaker. The beaker shall be filled so that the fluid level r
25、eaches the marking (notch) on the spindle shaft (approximately 570 to 600 mL of air bubble free fluid is needed).x For the UL Adaptor, the container size/form is defined by the adaptor.3.3.6 Guard LegThe guard leg shall be attached to the viscometer when using the LV1 or LV2 disc. The guard leg is n
26、ot used with the UL adaptor3.3.7 Rotation SpeedThe viscometer shall be set at a rotation speed of 0.3 rpm before inserting the spindle into the fluid.SAE INTERNATIONAL AS9968 Page 4 of 53.3.8 Spindle Selection3.3.8.1 Original/Baseline Measurement (for Fluid Manufacturers)The spindle to be chosen for
27、 an original/baseline measurement depends on the viscosity of the fluid/fluid dilution.x For viscosities up to 2000 mPa.s, the Brookfield UL Adaptor with corresponding spindle shall be used.x For viscosities between 2000 and 10 000 mPa.s, the Brookfield spindle LV1 shall be used.x For viscosities be
28、tween 10 000 and 20 000 mPa.s the following spindle shall be used:LV1: For fluids/fluid dilutions with a production viscositiy range/typical dilution viscosity range below 20 000 mPa.s.LV2 disc: For fluids/fluid dilutions with a LOWV below 20 000 mPa.s and a production viscosity range/typical diluti
29、on viscosity range partly or completely above 20 000 mPa.s.x For viscosities equal to or above 20 000 mPa.s, the Brookfield spindle LV2 disc shall be used.When viscosity results are outside the range given for the used spindle, the measurement shall be repeated using the appropriate spindle.3.3.8.2
30、Comparative Measurement (for Fluid Users)To compare results of two viscosity measurements, these measurements must be made using the same spindle. Therefore a comparative measurement shall use the same spindle as was used for the original/baseline measurement.NOTE: Typically, viscosities of anti-ici
31、ng fluids are compared to the fluids LOWV. In this case, measurements must be made using the spindle that was used to determine the LOWV. The spindle number used is typically published with the LOWV.3.3.9 Spindle InsertionAny air bubbles clinging to the flat bottom side of the spindle must be avoide
32、d. This may be accomplished by inserting the spindle in the fluid sample at an angle (approximate 30 to 45 degrees) to the vertical, then put it upright and attach it to the device while keeping the spindle in the fluid sample.3.3.10 Measurement DurationThe viscosity reading shall be taken exactly 1
33、0 minutes after spindle rotation is started.4. INTERPRETATION OF MEASUREMENT RESULTSViscosity values obtained using the measurement method described in this AS can only be compared with other viscosity values if these have been established with exactly the same method, including the same spindle and
34、 container size/form. Other methods (including spindle and container size/form) may produce different values.5. REPORTThe report shall include, at a minimum:x a statement that measurements were carried out according to this method (AS9968);x all measured viscosity values;x for each measured viscosit
35、y value, all parameters used to obtain this value (i.e., fluid temperature, spindle, container size/form, rotation speed, and measurement duration).SAE INTERNATIONAL AS9968 Page 5 of 56. NOTES6.1 A change bar (l) located in the left margin is for the convenience of the user in locating areas where t
36、echnical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only.PREPARED BY SAE SUBCOMMITTEE G-12ADF, AIRCRAFT DEICING FLUIDS OFCOMMITTEE G-12, AIRCRAFT GROUND DEICING
