The meter must be connected in series with the circuit, not parallel. Turn on power. Testing Diodes Set the switch to the →+ position. Red lead to VΩmA , black to COM .
To ensure accurate measurements, calibrate your multimeter annually or as needed. Follow these steps:
RadioShack 24-Range LCD Digital Multimeter (Cat. No. 22-805)
If the voltage is unknown, select the highest range setting first to avoid overloading the meter.
Turn the rotary switch to the appropriate or V~ (AC) position. radio shack 24 range digital multimeter 22-805 manual
: Always discharge capacitors in a circuit before attaching test leads for resistance or diode testing. Battery Maintenance : The meter typically uses a 9V battery
Features a serial RS-232 port for real-time data logging and readings on a computer. Safety Rating: CAT II (600V). Core Button Functions
When the battery weakens, the low-battery indicator icon will appear on the display. Inaccurate readings often stem from low voltage supply. Replacing the Battery and Fuse
was for many years a staple in home workshops, hobbyist benches, and toolboxes. Known for its affordability, portability, and decent accuracy for non-industrial tasks, this meter is a versatile, entry-level troubleshooting tool. The meter must be connected in series with
The input value exceeds the current range setting. Turn the rotary switch to the next highest setting.
: Selects the primary parameter you want to test (Volts, Amps, Ohms, Diode, Continuity).
Move the red lead to the 10A MAX jack. Set the rotary switch to the 10A position. Limit high-current testing to less than 10 seconds per minute to prevent overheating. 🔧 Maintenance and Troubleshooting Battery Replacement
: Integrated RS-232 serial interface for data logging to legacy or modern emulated desktop platforms. Input Impedance : High input impedance ( Red lead to VΩmA , black to COM
: To replace a blown fuse or the battery, you must remove the screws on the back cover. The 200mA range is fuse-protected, but note that the high-current 10A/20A terminal is often not fused. Manual Availability
The Model 22-805 is a compact, portable digital multimeter (DMM). It features a high-contrast liquid crystal display (LCD) and a 24-position rotary selector switch. Key Technical Specifications 3.5-digit LCD with a maximum reading of 1999
If current measurements stop working, replace the internal fuse with an identical 250mA, 250V fast-acting fuse. Troubleshooting Common Issues