HOW TO READ DECIBLES (DB)
Note: In order to eliminate the DC components I the circuit, connect a O. 1 microFarad
Capacitor, or larger, in series with one of the Test Leads.
1. The db arc is 4th down, in Red.
2. Connect Red Short probe to + Jack, Black to – Jack.
3. Set switch knob selector to 10V AC Range, read direct on upper db arc, -20 to 22.
4. For measurement above the basic db range, set switch to the next highest AC Voltage
range and add db as shown in the table on the scale plate.
ACCESSORIES
Battery-Replace with "AA" Battery.
Fuse-Replace with A.W. Sperry Instruments Inc. Part # F-7 Fuse.
Test Leads-Replace with A.W. Sperry Instruments Inc. Part # TL-34 Test Leads.
IN STOCK- AT YOUR LOCAL WHOLESALER
GENERAL USAGE & MAINTENANCE
THINK SAFETY - ACT SAFELY.
DO NOT SOLDER WIRE ACROSS THE FUSE CLIPS, OR RE-INSERT BURNED
OUT FUSE WITH METAL FOIL ENCLOSING IT OR BYPASS THE SAFETY FUSE IN
ANY WAY.
DO NOT exceed the published maximum for each function.
DO NOT polish the window or attempt to clean it with cleaning fluid, kerosene or
gasoline - damage will result.
When volt measurements are completed, FIRST remove the Test Leads from circuit
being checked, AND THEN remove Test Leads from instrument jacks.
Remove grease and grime with a clean dry cloth.
When instrument is NOT in use, set Switch knob to “OFF”.
When measuring OHMS, MAKE SURE the circuit being checked is DEAD, completely
DE-ENERGIZED.
Avoid severe continuous mechanical shock or vibration, extreme temperature or very
strong magnetic fields.
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