what do these features do on a multimeter??

i went to this website to help me find a multimeter and these features were in the filter that i either dont know what they are/do or know if they are important. so can anyone tell me what these features do on a multimeter, what they are used for, and if they are important.

1. frequency
2. period
3. ratio
4. temperature
5. Vp-p
6. diode
7. continuity
8. 2/4 wire resistance
9. conductance
10. dBm
11. duty cycle
12. inductance.
13. pulse
14. TRMS
15. capacitance

note: they have said that capacitance doesnt need to be a feature do to problems and i want to use a multimeter to simple to complex electronic projects like on instructables.com and robotics when i get to that level. thanks

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leader1 (author) 7 years ago
ok. well i also see these brands/manufacturers and i dont now which are bad or good. can you help? they are:

1. Agilent HP
2. BK Precision
3. Fluke (i know they are the best but just putting it to compare to others)
4. Keithley
5. Amprobe
6. Extech Instruments
7. GW Instek
8. Tektronix

.  Never used an Agilent.
.  The last time I used a BK Precision was in the 1980s, but had good luck with it.
.  I liked every Fluke I used.
.  Never used a Keithley.
.  Amprobe is up there with Fluke - great products.
.  The only Extech I used was a "value model." Seemed like a decent cheap meter, but I didn't check its calibration or anything.
.  Never used a GW.
.  Tektronic bench gear is great. I haven't used any of their portable VOMs/DMMs, but assume they would be the same high-quality stuff.
leader1 (author) 7 years ago
so how much of this is useful to do the electronic projects on here and other stuff like robotics?
.  Depends on what you are doing. A lot of DIYers don't use frequency/period. Very few have any use for dBm. If you are only using 50/60Hz, then TRMS doesn't mean much. &c, &c, &c.
.  For most DIY work, a VOM (Volt-/Ohm-/milliam-meter) with a diode tester and continuity checker will do what you want. (Accurate) Capacitance used to be an expensive option, but is standard equipment on a lot of meters nowadays.
.  If you really need things like Vp-p, conductance, duty-cycle, &c you will know that you need them and not have to ask. ;)
NachoMahma7 years ago
.  In a nutshell:
1. frequency - measures how fast polarity changes (cycles/second)
2. period - inverse of frequency (seconds/cycle)
3. ratio - not sure
4. temperature - thermocouple and/or RTD input to measure average molecular motion
5. Vp-p - peak-to-peak voltage
6. diode - for testing diodes
7. continuity - test that a circuit is complete or shorted
8. 2/4 wire resistance - not sure
9. conductance - inverse of resistance (mhos or Siemens)
10. dBm - power ratio of measured power referenced to one milliwatt (mW)
11. duty cycle - time on/time off
12. inductance - measure inductance of a coil/inductor
13. pulse - probably just a pulse catcher (comes on when pulse detected and stays on until reset)
14. TRMS - True Root Mean Squared. Will accurately measure RMS voltage at different frequencies
15. capacitance - measure the capacitance of a capacitor

.  Search the Web for more info.