Range Doubler (220-0215) Controls and Functions Faxback Doc. # 6538 Multitester Scales - Three-color scale with mirror, green scale for ohms readings, red scale for ACV readings and black scale for DCV, DCA, and dB readings. Zero-Adjust Screw - Use to set the pointer exactly over the 0 at the left side of the AC/DC scale for ACV, DCV, DCA, and DB measurements. Ohms-Adjust Control - Use to bring the pointer to 0 on the OHMS scale when measuring resistance on the OHMS range. Range-Doubler Switch - Use to divide the range setting by two if the meter reading is not in the upper half of the scale during the initial measurement. -COM Jack - Plug in the black test lead here for all measurements. Do not connect this jack to any source of more than 500 volts with respect to earth ground. +V-Ohms-A Jack - Plug in the red lead here for all measurements, except DC voltage measurements above 250 volts and DC current measurements above 500 mA. The maximum AC voltage measured here is 1000 VAC. +1000V DC Jack - Plug in the red lead here when measuring DC voltage between 250 and 1000 volts. +10A DC Jack - Plug in the red lead here only when measuring DC current of 500 mA to 10A. INCLUDED ACCESSORIES Spare Fuse - Cat. No. 270-1271 - 250V, 0.5A, Stored inside the tester. Banana Plug Style Test Leads - Cat. No. 278-704. (BR/all-07/11/94)