Extech Ex330 - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: September 18, 2020, 12:02:10 pm
content: Does anyone have a guide for using this for a total beginner?I bought it ages ago and watched guides on using a multimeter but because this dials are different to watch I see people showing I never know which setting is correct. For simple stuff like checking a battery or check a fuse in a plug. Never sure what to point it at on the dial.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: September 18, 2020, 12:17:15 pm
content: Honestly, read the manual.Other than that, get an Arduio and pratice taking measurements.

author: MosherIV
author_rank: Super Contributor
timestamp: September 18, 2020, 12:23:21 pm
content: Rotate dial to 'V' (voltage measurement mode) to measure battery voltage. Voltage is not always a good indication of how much is left in battery. Fresh/new batteries should be higher than the advertised battery voltage eg 1.5V new reads 1.55V or even 1.6VRotate dial to '' to test fuse. Should measure very very low for a good fuse. Show 'OL' (over load or open circuit) if fuse is bad.

author: CharlotteSwiss
author_rank: Frequent Contributor
timestamp: September 18, 2020, 12:33:11 pm
content: manuals are not optional to be set aside; you take it and start from page 1 to the end, in the meantime you experiment the measurements, you will see that you will make great progress; then if you have doubts about some measurements ask here, many people will help you; but you have to at least start doing something ...

author: Electro Fan
author_rank: Super Contributor
timestamp: September 18, 2020, 03:53:06 pm
content: A few basic tips (for the EX330 or other Digital Multi Meters in general):1. The manual is probably your best way to make sure you understand what each selector symbol intends:https://www.instrumart.com/assets/Extech_EX330_Manual.pdf2. Make sure you keep the black probe seated in the COM socket (middle socket on the EX330).3. For starters (just to be extra safe with the meter)unless you are measuring current,keep the red probe in the right (as you face the meter) socket.Note: On the EX330 you can also use the red probe in the right socket for milli (m) and micro (u) amp current measurements, but when starting out to be safe when measuring current - in case you don't know how much current you might encounter - put the red probe in the left (10A) socket. In general, if you are needing refresher help with a DMM stay off current measurements until you familiarize yourself with how to put the meter in the circuit for current measurements. (See #7 below.)4. With suggestions 1-3 out of the way for the EX330, ie, making sure to have the black probe in the middle socket and the red probe in the right socket, maybe start with putting the meter in Continuity Mode (it is the sideways increasingly larger umbrella-looking beeper symbol, and it is on the dial setting that is shared with the Diode, Resistance, and Capacitance settings.) If still in doubt, the Continuity Mode is one setting to the left of OFF. Once you are on that dial setting, keep pushing the MODE button until you see the Continuity Mode symbol appear in the display. (Dial settings with more than one mode can be found by toggling through the settings with the MODE button). Once you have this set properly you can put the two probes on a piece of wire and you will hear a beep, or maybe continuous beeps. This indicates that there is a functioning ("continuous") electrical path between the probes. You can test an incandescent light bulb the same way - put one (either) probe on the end of the bulb and the other probe on the screw-in portion of the bulb - if you get a beep the bulb is good, if not, the bulb is bad. This is the same basic approach (with one probe on each end) to use for testing to determine if a fuse is good or bad. It is a great basic test to determine if there is a closed (functioning) electrical path between two points. If there is no path and therefore no beep, you have an open circuit.5. Next test some batteries for voltage. You can try AAA, AA, C, D, 9 volt, etc. Here you will want to have the dial set on VDC (Voltage Direct Current). The red probe goes on the battery + and the black probe goes on the battery -. If you get this backward the meter should show you a minus sign (the -). This won't hurt the meter or the battery or you, but it will remind you to maintain appropriate polarity. Fresh batteries should meet or likely somewhat exceed their rated value. Just remember, some measurements don't care much about polarity, but some (such as capacitors and diodes) do - so always observe the DUT (Device Under Test) markings and try to get polarity (+ and -) correctly probed.6. If you think you are measuring battery voltage and get a strange reading, check to make sure the dial is on VDC, not VAC (Voltage Alternating Current) or some other setting. This can happen, even experienced users sometimes go a tad too fast and set the dial in the wrong place. Until you get more experienced and confident with the meter it's probably good to stay away from high (wall) AC voltage. One thing to note on the EX330 is that while it will measure voltage in AC, it will show average readings rather than RMS readings. If you are going to be doing any significant amount of AC work you should read up on the difference between average and RMS.7. If you really get into using the DMM for more than an occasional voltage or continuity check you should watch some YouTubes on how to use the meter to measure current. It is a very valuable measurement and it simply requires you to understand the concept of putting the meter into the circuit (as opposed to measuring voltage across a Device Under Test).8. Except for not having the RMS feature the EX330 looks like a very nice meter that has very clearly marked dial settings and buttons. Stay safe and enjoy!