1. How to use the STELR multimeter

2. Multimeter Features Input jacks Turning on (and off) LCD display
How to measure voltage
How to measure current
How to measure resistance
Other measurements
Use of the ‘hold’ button
Use of the ‘backlight’ button

3. Features of the STELR multimeter

4. LCD display
Multimeter

5. LCD display
Hold button
Multimeter

6. LCD display
Hold button
Rotary switch
Multimeter

7. LCD display
Hold button
Rotary switch
Shock-proof case
Multimeter

8. Multimeter LCD display Hold button Rotary switch Shock-proof case
Input jacks
Multimeter

9. Multimeter LCD display Back light button Hold button Rotary switch
Shock-proof case
Input jacks
Multimeter

10. Please also refer to the instruction leaflet accompanying each multimeter.

11. Input jacks

12. The centre jack is a common negative
Input jacks

13. The centre jack is a common negative
The right jack should be used as positive for all measurements except when measuring between 200mA and 10A
Input jacks

14. Input jacks

15. The centre jack is a common negative
The left jack should only be used as positive for when measuring between 200mA and 10A. For example when using the wind turbine.
The centre jack is a common negative
Input jacks

16. Input jacks

17. Tuning the multimeter on

18. Rotary switch in ‘off’ position.
Multimeter

19. Turn rotary switch to any other setting to turn on
Multimeter

20. Multimeter The display will activate once the multimeter is turned on
Turn rotary switch to any other setting to turn on
Multimeter

21. If the display does not activate, it means either the battery is flat or the fuse has blown. Go to
to find out how to change the battery and the fuse.
Multimeter

22. If the display does not activate, it means either the battery is flat or the fuse has blown. Go to
to find out how to change the battery and the fuse.
The multimeter will automatically power off if unattended for over 5 minutes. To reactivate, turn to off and then to any other setting.
Multimeter

23. LCD display

24. If the battery is low, a battery symbol will appear in the top left corner of the display.
LCD display

25. If the battery is low, a battery symbol will appear in the top left corner of the display.
It is suggested that the battery be replaced as soon as the low battery symbol appears.
LCD display

26. A small number is displayed at the bottom of the screen.
LCD display

27. LCD display A small number is displayed at the bottom of the screen.
The number corresponds to the rotary switch setting and indicates the maximum reading for that setting.
LCD display

28. A reading of a 1 followed by a decimal point but no zero, indicates that the multimeter is off-scale.
LCD display

29. A reading of a 1 followed by a decimal point but no zero, indicates that the multimeter is off-scale.
In this case the multimeter is set to 2V, so the ‘1.’ indicates that more than 2V is being passed through.
LCD display

30. A reading of a 1 followed by a decimal point but no zero, indicates that the multimeter reading is ‘off-scale’.
The rotary switch should be moved to a higher value to allow proper measurement.
In this case the multimeter is set to 2V, so the ‘1.’ indicates that more than 2V is being passed through.
LCD display

31. LCD display A negative reading is indicated by the minus symbol.
The this means that the current is flowing in the opposite direction.
LCD display

32. Measuring voltage

33. There are five different DC voltage settings
Measuring voltage

34. Measuring voltage There are two different AC voltage settings
There are five different DC voltage settings
Measuring voltage

35. Measuring voltage There are two different AC voltage settings
There are five different DC voltage settings
There are no STELR activities that require the use of AC. Students should never use these settings.
Measuring voltage

36. Measuring DC voltage There are five different DC voltage settings
When measuring voltage, always use these two sockets
Measuring DC voltage

37. 0 – 600V
Measuring DC voltage

38. 0 – 600V
0 – 200V
Measuring DC voltage

39. 0 – 600V
0 – 200V
0 – 20V
Measuring DC voltage

40. 0 – 600V
0 – 200V
0 – 20V
0 – 2V
Measuring DC voltage

41. 0 – 600V
0 – 200V
0 – 20V
0 – 2V
0 – 200mV
Measuring DC voltage

42. Using different DC voltage settings
Always start measuring with the meter set to the highest voltage and then move the rotary switch to lower settings until the most accurate reading is achieved.
Here, the three volt STELR battery pack will deliver just under 3V.
The rotary switch is set to the highest value (600V) and the multimeter reads 1V.
Using different DC voltage settings

43. Using different DC voltage settings
The rotary switch is has been moved to 200V and the multimeter now reads 2.8V.
Using different DC voltage settings

44. Using different DC voltage settings
The rotary switch is has been moved to 20V and the multimeter now reads 2.99V.
Using different DC voltage settings

45. Using different DC voltage settings
The rotary switch is has been moved to 2V. Since the battery is delivering more than 2V, the multimeter reads
‘1.’
Using different DC voltage settings

46. Using different DC voltage settings
The rotary switch is has been moved to 2V. Singe the battery is delivering more than 2V, the multimeter reads
‘1.’
This indicates an ‘off-scale’ error. The rotary switch should be returned to the previous, most accurate position
Using different DC voltage settings

47. Using different DC voltage settings
The rotary switch is has been returned to 20V and the multimeter now reads gives the most accurate reading.
Using different DC voltage settings

48. Measuring current

49. There are five different DC current settings
Measuring current

50. 0 – 200A
0 – 2mA
0 – 20mA
0 – 200mA
0 – 10A
Measuring current

51. There are four DC current settings for measuring lower currents.
When measuring current, use these two sockets for currents below 200 mA.
Measuring current

52. Measuring current When 10A has been selected
Use these two sockets for currents between 200 mA and 10A.
Measuring current

53. These two sockets (used for currents below 200 mA) are protected by a 200mA fuse.
Measuring current

54. These two sockets (used for currents below 200 mA) are protected by a 200mA fuse.
If overladed the fuse will blow.
Measuring current

55. These two sockets (used for currents below 200 mA) are protected by a 200mA fuse.
If overladed the fuse will blow.
This most commonly happens if
the multimeter is connected directly to the power supply
The multimeter is connected directly to the wind turbine with no load
Measuring current

56. To prevent blowing the fuse, students should be encouraged to always begin measuring current using the 10A setting.
Measuring current

57. For detailed instructions on how to change the fuse in the STELR multimeter go to:
Spare 200mA fuses are supplied in the STELR Renewable Energy teacher kit.
Replacing the fuse

58. Measuring resistance

59. There are five resistance settings
Measuring resistance

60. Measuring resistance There are five resistance settings
When measuring resistance, use these two sockets.
Measuring resistance

61. 0 – 2 MΩ
0 – 200 kΩ
0 – 20 kΩ
0 – 2 kΩ
0 – 200 Ω
Measuring resistance

62. Other measurements

63. Other measurements
There are two other settings on the multimeter that can be used for testing transistors and diodes.
These are not required for use as part of the STELR program, but may be of general use in other programs.

64. Set the rotary switch to this position
Diode testing

65. Diode testing Set the rotary switch to this position
Connect the black lead to the COM socket.
Connect the red lead to the VΩmA socket.
Connect the black lead to the cathode and the red lead to the anode of the diode to obtain a reading.
Diode testing

66. Set the rotary switch to the hFE position
Transistor testing

67. Transistor testing Determine whether the transistor is PNP or NPN.
Set the rotary switch to the hFE position
Transistor testing

68. The hold button

69. Using the ‘hold’ button
When using the wind turbine, a fluctuating current is measured.
This is a result of the variable wind flow from the fan.
Pressing the hold button, ‘freezes’ the reading.
Pressing the hold button a second time returns the meter to the variable measurements.
Students can be encouraged to take three readings , five or 10 seconds apart, and average them for a more accurate measurement.
Using the ‘hold’ button

70. Using the ‘hold’ button

71. The back light button

72. Using the backlight button
Once the button is pressed, the backlight will illuminate the LCD display. The backlight will stay on for three minutes.
Using the backlight button

73. Using the backlight button
Once the button is pressed, the backlight will illuminate the LCD display. The backlight will stay on for three minutes.
It is recommended that use of the backlight button is minimised, as it tends to drain the battery quite quickly.
Using the backlight button