United States Army X-ray manual / authorized by the Surgeon-General of the Army ; prepared under the direction of the Division of Roentgenology.

Date:
1920
Catalogue details

Licence: Public Domain Mark

Credit: United States Army X-ray manual / authorized by the Surgeon-General of the Army ; prepared under the direction of the Division of Roentgenology. Source: Wellcome Collection.

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    ment current of a Coolidge tube is not entirely steady. Thus, if the tube current in the case cited changed from 10 to 15 ma., with a rheostat control, the radiation would be reduced in quantity from 32 to 25 arbitrary units and also would be much less penetrating; while with the auto- transformer the same change would result in an increase 80 7O Pesce HAH = KV HAS per a0 a 1 ican eae Ve Gaane 3 ae SGSGE a en BeS8a7 2 (0 BHGBEEE Ht j eee: aan Vinee fete | sstniits SEE mia 50 atts oo 1/00 4 EEE SreECHEEt eae 80 O +] aman sans raza nee TI HH HEE EEE EEE SEE Ht mse one eet 30 HEHEHE He 60 oteper naa a Beeste eae weeny cae \enat SAR aii ats HEE 20 Fats Pct ot seers gereccevesraeeres Hie 140 THEE i t PEELE NEL is boone oe see { ORT EEN S babe oe ee a = sae Ee Hare SAEEEaresf aaa fold fobgd fast oastd coed eatec toed tans toad faait oatadt : O 10 .20 30 -AO .50..60 70-160 GO. WOO Fie, 18. Relation of x-ray production on two types of control. On rheostat control we have AC as the voltage-current line. Voltage ordinates at the left. DH, corresponding x-radiation quantity, ord- inates at the right. AB, autotransformer chart line. DF, corre- sponding quantity line. Quantity in arbitrary units. in quantity from 32 to 50 units very slightly less pene- trating than at 10 ma. ‘“‘Inductance’’ Taps.—Instead of controlling completely by variation in the applied voltage, in some instances the winding ratio of the x-ray transformer is variable by a dial switch which cuts in more or less turns of the trans- former primary. The lowest ratio of step-up corresponds to the complete primary and, since the secondary winding