Multimeter

Analog multimeter

My first multimeter was a Radio Shack Micronta model 22-220 meter.  It was purchased in 1989 from our local radio shack for a sale price of $39.  At the time of purchase was trying to repair a computer and needed to test voltage.  Over the years, I have used it as a continuity meter and to measure voltage of plugs. 

Features of the meter include: 

1. Large light weight plastic case, analog dial and 2 probes.

2. Front panel has a mirror for enhanced reading of the meter's analog dial.

3. Measures both AC and DC from 1 to 1000 volts, with a 10MΩ DC input impedance. 

4. It has typical ohms ranges from X1 to X100K

5. Makes noise when testing continuity.

6. Measure DC current using the probs from 100μA to 300mA, plus a separate socket for DC 10A.

Thoughts and Hacks on Analog Meter

1. Remember to turn off meter to conserve batteries.

2. The meter needle will drift off zero or not return to zero after taking a measurement.  Adjust will solve some of the problem but replaced batteries to solve.  

3. Never blew any fuses.

The meter may not have been the best but purchased local and I could afford it.  Radio Shack catered to hobbyist and professionals with affordable the electric parts and equipment.  

Digital Clamp Multimeter

The need to measure amps caused me to look for a clamp meter.   The selection process was daunting because everyone seems to make or sell multiple styles.  I was looking for an affordable but functional meter.  

I purchase a VEVOR Digital Clamp Meter T-RMS with AUTO select on January 30, 2024 for $34.  The AUTO select is a smart function so no switch to move between tests.  The Clamp meter comes with 2 AAA batteries, 2 probes for most measurements, and a temperature probe.  It has a nice case for storage.  The power turns off after 15 minutes no activity.

Features of the meter include: 

1. 600 AMP clamp multimeter for both AC and DC.  Do not us on an electric fence.

2. Measures AC or DC Voltage

3. Tests resistance and resisters

4. Checks Diodes

5. Beeps if there is continuity

6. Non-contact sensor (NCV) to measure the strength of electromagnetic fields without touching any wires  

7. LED flashlight and lighted display

8. Accurate readings with Root Mean Square (RMS) averaging with 0.0001 millivolt resolution

9. Data storage   

Measuring Amps

Do not use on Electric Fence!

Amps use the clamp and require special setup of the meter.  

1. Make sure that all the test leads have been removed from the meter.

2. Turn on meter and wait 5 minutes

3. If measuring DC Amps 

   1. Briefly press the "sel" button until both the symbol DC and A display.

   2. Zero display "NC " button once to zero.

   3. Clamp jaw around one wire and center.

   4. Take reading.

4. If measuring AC Amps

   1. Briefly press the "sel" button until "Auto" is displayed.

   2. Clamp jaw around one wire and center.  Use line splitter if needed. 

   3. Take reading.

Thoughts and Hacks on Digital Clamp Meter

1. Probes feel a little cheap but work.  May buy better ones.

2. The aaa batteries that came with unit lasted a week.  

3. Tested aaa batteries and could cull out those with low volts (1.25 vs 1.5 volts).  This was impossible with the analog meter. 

4. Added a Thsinde AC Line Splitter to allow easy amp measures on 120v cords ($12).