Specifications
DIGITAL MULTIMETER 
  OPERATING INSTRUCTION
Appendix: 
Conversion between luminance and light intensity: 
E = I / r 
2 
where  E --- luminance, unit: Lux  
I --- intensity of light source, unit: cd  
r --- distance between illuminant surface of light source 
and light detector, unit: m. 
When  making  measurement,  the  shortest  distance 
between the illuminant surface of the light source and the 
light  detector  should  be  larger  than  15  times  of  the 
maximum size of the illuminant surface of the light source 
(or the light sensor). 
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DIGITAL MULTIMETER 
  MAINTENANCE
5. MAINTENANCE 
5.1 REPLACING THE BATTERIES   
  WARNING 
To avoid  electric shock, make sure that  the test 
leads have been clearly move away from the circuit 
under  measurement  before  opening  the  battery 
cover of the meter. 
5.1.1   If the sign “ ” appears, it means that the batteries 
should be replaced. 
5.1.2   Loosen the  fixing screw  of  the  battery cover and 
remove it. 
5.1.3   Replace the exhausted batteries with new ones. 
5.1.4   Put the battery cover back and fix it again to its origin 
form. 
NOTE: 
Do not reverse the poles of the batteries. 
5.2 REPLACING FUSE 
5.2.1   Fuses rarely need replacement.   Almost all blows are 
the result of operation errors. 
5.2.2   Loosen the  fixing screw  of  the  battery cover and 
remove it. 
5.2.3   Replace the blown fuse  with one  at the specified 
rating. 
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