1、 FORD LABORATORY TEST METHOD BQ 104-02 Date Action Revisions 2000 11 10 Revised Editorial no technical change A. Cockman 1990 06 26 Printed copies are uncontrolled Page 1 of 3 Copyright 2000, Ford Global Technolog ies, Inc. HUMIDITY RESISTANCE TESTING Application This procedure is a method for prepa
2、ration of parts and cabinets for determining the resistance to humidity of various parts. Note: The procedure is not to be used for glazing materials. Apparatus Required Humidity Cabinet The humidity cabinet consists of a test chamber, a saturator tower, a supply of suitably conditioned compressed a
3、ir, specimen supports, provision for heating the chamber and suitable controls for maintaining the desired temperature. Top open ing, front opening, or walk - in type cabinets are satisfactory. Source: Harshaw Chemical Co., Equipment Section 15583 Brookpark Road Cleveland, Ohio 44142 or equivalent.
4、Size The cabinet shall be of sufficient size to test adequately the number of parts required by the Engineering Material Specification without overcrowding. Satisfactory correlation between test cabinets is obtained when the test chamber is no less than 0.7 m - approximately 0.6 x 0.9 x 1.2 m. Cabin
5、ets smaller than this may be difficu lt to control within the limits specified. Construction Materials Cabinet The test chamber shall be constructed of epoxy - lined steel or equivalent material. Specimen Racks Specimen racks and supports shall be constructed of plastic, vinyl coated steel, or equiv
6、alent materials. Shelves shall be provided with drain holes so that test specimens do not rest in pools of collected water. Plumbing All piping inside the test chamber shall be plastic or hard rubber. FORD LABORATORY TEST METHOD BQ 104 02 Page 2 of 3 Copyright 2000, Ford Global Technologies, Inc. Ve
7、nts Vents shall be so placed that moistu re is circulated freely about the test specimens and also exhausted to the outside of the cabinet. Saturator Tower The compressed air, after cleaning and before entering the cabinet, shall be passed in finely divided bubbles through a saturator of corrosi on
8、resistant materials, containing heated distilled or deionized water, controlled at the specified temperature. The distilled or deionized water in the saturator tower should be changed on a periodic basis, depending on water purity, to prevent excessive accumulation of impurities from the air. Temper
9、ature The temperature of the test chamber shall be maintained by heating elements in the walls of the cabinet through suitable controls. The test chamber shall be insulated by water jackets or other suitabl e means between the exterior walls of the cabinet to prevent cold spots where condensation on
10、 test specimens may occur. Air Supply The air supply to the nozzles or air distribution pipe shall be free of oil and dirt or other objectionable impurities. Not e: A water scrubber or suitable cleaning material (a minimum of 600 mm of sheeps wool, excelsior, slagwool, activated aluminum, or equival
11、ent) may be used to clean the air supply of oil and dirt. Humidity and Temperature Control Thermistor Psychrometer Source: Harshaw Chemical Co., Equipment Section 15583 Brookpark Road Cleveland, Ohio 44142 or equivalent. Materials Required Distilled or Deionized Water 20 micromhos/cm at 25 C maximum
12、 conductivity (ASTM D 1125) FORD LABORATORY TEST METHOD BQ 104 02 Page 3 of 3 Copyright 2000, Ford Global Technologies, Inc. Cabinet Operating Conditions Relative Humidity 95 - 100 % Moist air shall be circulated in the cabinet by a fan or other suitable means. This is accomplished in top opening ca
13、binets by passing air from the saturator tower through a plastic air distribution pipe under 150 - 200 mm of dis tilled or deionized water in the bottom of the cabinet. Holes in the plastic pipe face downward and are evenly spaced 1.6 mm diameter holes approximately 150 mm apart. The pipe extends th
14、e length of the cabinet midway between the walls. Air shall be bub bled through the pipe at approximately 7 - 14 kPa line pressure so that the air is in motion and the humidity maintained as specified. No condensation of moisture shall be permitted to form on the test specimens so as to form droplet
15、s on the parts being t ested. There shall be no dripping of water from one specimen to the other. Temperature: 38 +/ - 1 C Saturator Tower: 43 +/ - 1 C Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmos phere of 23 +/ - 2 C and 5
16、0 +/ - 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure 1. Clean samples with a solution which will not harmfully affect the surface of the material being tested nor leave a residue which could affect the test or
17、 contaminate the condensate. Note: The test chamber shall be cleaned at least every 60 days to remove any contamination which may be introduced from the test specimens and when the dissolved solids (in the water) exceed 20 ppm (40 micromhos/cm) or when he pH is not in the 5.5 - 7.5 range. 2. Unless
18、otherwise specified, parts will be supported or suspended in “car position“. In instances when the car position is vertical, the part shall be inclined 15 degrees from vertical. 3. The time of exposure in the humidity cabinet shall be as specified in the Engineering Material Specification or Enginee
19、ring Drawing. 4. Opening of the cabinet during the test shall be kept to a minimum to pr event disturbing the equilibrium of the cabinet. 5. Examination for failure shall be as specified in the applicable Engineering Material Specification or Engineering Drawing. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
