Document Dvrd0OM8QDq9evgVy02ENDZpd

JT {<* A VcL | | It; DIRECTIONS FOR TEST SO. SPBJgQTt Dielectric Strength of Liquid Arcelor METHOD t This method Applies to mineral oils sad oil substitutes used for insulating purposes. Apparatus Capacitance Bridge Oeneral Radio Oo., Type T16-AM Oathods Ray Hull Detector * Type 707-a Oscillator * Type tO*-L Constant Temperature Oven Canco-DeXhotlnaky #95060 Variable Air Condenser Oeneral Radio Co., Type 334-P 1500 ee. Pyrex Beaker ?gooedure "" Eleotrode end beaker suet be cleaned as directed under "Clean ing Apparatus for Dielectric Constant", and bs at 100*0# Beat Aroelar In the ean to 106*C. Pour ot*t alaotzoda until ; plates and ceramic Insulation is oovered. Sonaect leads. Stir with ! thermometer outside even until temperature reaches 101*} place In oven which has been carefully adjusted to 100*0. At tbs time Sem ple is plaoed la ores Its tempareture showId bare fallen belov 90*0. - Connect leads to capacitance bridge, observing that the lead from Insulated elds of condenser goes to Insulated terminal on bridge. Balance bridge carefully according to direction under "Balancing Capacitance Bridge". Until Aroelor end ovmt temperatures have br ooms identical the bridge balance rill constantly shift. After oven temperature reaches 100*0., maintain bridge balance until no pronounced shift Is evident. Record reading of capacitance scale multiplied by multiplier setting. Dielectric Constant Capacitance Is Aroelor at 100C. Capacitance ia air at 100*0. I Balanelng Capasltaacs Bridge Condensed procedure. Operator should reed operating instruo- ; tloa for Hull Detector for complete details. 1. Connect to power supply leads to oscillator and sail detec tor. Ground the oscillator. DSW 330635 STLCOPCB4077279 3 Pngs Ho. Dielectric Strength of Liquid Aroelor -- Test 14-06-41 2. Turn on oscillator by pushing 9000 ohm, 10 multiplier, 100 cycle frequency button*. Adjust harmonic oostrol until oscillation begins os shown by eloeing of sector in oathodo rtj tube. 3. (hi null dotsotor turn brilliance knob to extreme loft, tho focus knob to extreme right, gain sontrol to extrema left, snoop amplitude at mid-scale position, tho snoop frequency switch on lino side. 4 Turn on power suit eh, lighting pilot light. 9. bait fifteen seconds, turn brllllanee knob to extreme right. 6. Adjust foous and billianoo knobs until sharp fins lino* 7. Connect external terminals on detector to output ternInals on eedilator. 8wltoh sweep frequency to external side. j 8. Connect detector terminals of bridge to Input terminals of doteetor, taking oaro that the black vlro (ground wire) of the lead goes to grounded terminal on both ends of load. !; 9. Set gain control at mld-scalo and selectivity to extreme left, j Run sweep amplitude to extreme loft, obtaining vertical line. With ;! gain oontrol sake this about 1/4" long. 10. Vith turning control knob Obtain the maximum length of this line, keeping it always under 1/4 inch with gain knob. 11. Sot swoop amplitude to extreme loft. 12. 8et gain oontrol to giro vertical straight lino of about 3/8 inch. 13. Balance bridge by adjusting power factor and capacitance dials until only n dot remains on the aereea when the gain oontrol in at artramo right. 14. Sot swoop amplitude beyond mid-point, end slightly displace the power-factor dial to obtain n tilted ellpae. 19. Adjust phase control until this elUpa# sloses into s straight line Inclined to the horlsamtal. 29. Bring power-faetor dial book to balance position, which should restore the borlsoatal straight lino. Displace this control the same amount in tho opposlts direction. This should again tilt tha straight DSW 330636 STLCOPCB4077280 t i Page A. 3 : Dieleetrio Strength of Liquid Aroelor -- fast 14-06-41 ji I line bat la the opposite direction. Adjust phase control until thara is no tendency for tola line to apsa up when it la swung 30 degrees from horizontal la both directions* 17. Throughout these adjustments the other bridge oontrel (the capacitance dial) oust he in balance position. If the ellipse grad ually opens when the line is horizontal it aay ha brought beak to the line again by asking slight ehenges la thla control. If confusion results, balance both control* again as ia (13) and repeat the eue- eeedlng adjustments. Thla is the position of bridge balance: An alteration of the | power-factor control will tilt the line which does not open appreoia;j bla thru an angle of X* to the horizontal both ways; an alteration I- of the oapaoitanse dial opens the ellipse but does not change the inclination of the aajor axle. !i The apparatus nay be left in this balanced condition, turned eff ij by witching eff first the brilliance knob of the deteotor, than the !; power switch, then turning off the oscillator* ?or suooesslT* measurements the controls are not changed, the j apparatus left in adjustment. Then the following steps define the procedures 1. Connect nil leads ss previously directed including that from j anil detector to bridge. ' 8* Turn oa oscillator by pushing 100 oyols frequency button. | 3* Turn oa null deteotor, wait 15 seconds than turn on oathode j ray tube* Turn sweep amplitude to extreme left and adjust brllllcnee to obtain a fine vertical line oa screen. ' 4. Bring this lias to a dot by adjusting the two bridge controls. Initial adjustment is faollltated by having "Cain" control to left, bhea final adjustment Is obtained this knob must be at extrane right. 5. Thla dot remaining unchanged shows ooedition of bridge balance. Cleaning Apparatus for Dleleotrle Constant ! The onndeaser isremoved from Aroelor while still hot by suspend : lag it froa the plat* attached to the freae end allowed to drain. Haver handle condenser by the Insulated terminal. After allowing to cool ; somewhat a 50-60 mixture of benzene-oarbon tetraohlorlds is poured over oondonser into the beaker used in the test. After draining it is washed in a mixture of equal parts benzone--tetrachloride. It is then washed successively la three different mixtures of benzene-tetraohlorde, dreinlag thoroughly bstween washes, finally the eleetrode Is plaoed on clean paper and brought to 100* In oonstant tsmparatura ovan. I| DSW 330637 STLCOPCB4077281 i Bags So. 4 Dlslsctrie Strength of Liquid Aroolor -- Tent 14-06--41 The heaker is rinsed with the sleonlng mixture originally poured OYer the condenser, then washed with T.S.P. and hot water. After draining thoroughly It la dried at 100* in the oven. When handling the condenser the operator ehould never suspend It hy the ternlhal to the Insulated plates. 2/12/42 i i dS\N 330638 i; STLCOPCB4077282