Test/review of DMM Mastech MS8216

HKJ · 2018-04-09T14:20:24.000Z

DMM Mastech MS8216

This is a small pocket DMM with voltage, frequency, ohms and capacity.

The meter was in a clamshell pack. On the back is a the specifications.

In the pack was the meter and a manual in English.

The probes are small and they are not round, but ellipse shaped.

The probes are directly connected to the meter, no plugs and sockets.

The range switch is easy to turn, but the detents are not very strong and it is very easy to place the switch between ranges.

A pouch is included.

Two screws must be removed to get battery access.

Display

The above picture shows all the segments on the display.

Typical display during usage, it will show the selected range and value.

Functions

Buttons:

Rel: Store current display value and show all new values relative to this value.
H/D: This is short for Hz/duty cycle and will show frequency and duty cycle in both DC, AC and frequency mode.
D-H: This is the hold button and will freeze the display reading, until pressed again.

Selection of Rel and Hz/duty will disable auto ranging and it stays disabled

Rotary switch:

Off: Meter is turned off
VAC: Voltage AC, frequency and duty cycle.
VDC: Voltage DC, frequency and duty cycle.
: Ohm.
: Continuity.
: Diode.
: Capacitance.
Hz: Logical frequency input.

Input

This meter only have a red and black probe comming out, no other connections.

Measurements

Volt and frequency
- At 1V rms input on frequency the counter range is from 2Hz to 50kHz
- At 2V rms input on frequency the counter range is from 0.6Hz to 100kHz
- At 5V rms input on frequency the counter range is up to 290kHz
- Duty cycle works from 15% to 90% at 1kHz with 4Vpp, precision is within 3.0
- Frequency inputs do not need a zero crossing.
- 1V AC readings is 5% down at 2kHz
- Voltage input impedance is 10-11Mohm,
- mV input impedance is high below 1.5V and drops to 10Mohm above
- Frequency input is similar to mV input.
- Input protection is 600V AC/DC for voltage 250V AC/DC for frequency.
Current
- Meter cannot measure current
Ohm, continuity, diode and capacity
- Ohm needs about 3.4s to measure 100ohm
- Ohm is 0.42V open and 0.17mA shorted
- Continuity is moderate in speed (100ms)
- Continuity beeps when resistance is below 55ohm
- The beeper volume is very low.
- Continuity is 0.44V open and 0.17mA shorted
- Diode range uses 1.5V, max. display is 0.999V at 0.2mA, max. current is 0.55mA shorted
- 190uF takes about 40 seconds to measure.
- Rated overload protection is 250 VDC/VAC
Miscellaneous
- Current consumption of meter is 0.8mA except AC where it is 1.4mA
- Meter fails below 1.4V, battery symbol show at 2.4V.
- Readings will drift about 2 count when from when battery symbols shows to the meter fails.
- Viewing angle is good, except from top
- Display updates around 2 times/sec
- Will automatic turn power off after about 15 minutes
- The meter often need many display update to reach the final value.
- Weight is 82g without accessories, but batteries.
- Size is 110 x 78 x 13mm.
Probes
- Probe wire is a bit thin, they are 31cm long.

Capacity measurement waveform.

Frequency input resistance in voltage frequency position, V and mVDC is similar.

Frequency input resistance in voltage AC position.

Lowest capacity range is sometimes out of tolerance (Up to 8%) and next time I measure the same capacitor it is inside tolerance.

Tear down

I had to remove two screws, to open it, this is also required when replacing batteries.

The battery holder is for two button cells.

I had to remove 6 screws before I could get the circuit board out.

The buzzer is mounted on the frontplate.

On this side there is only two capacitors and holes for adjusting the 3 trimpot (VR1, VR2, VR4).

On the input is a PTC (R24), it is not used for all ranges. The main input resistor (R21 & R’21 2x5Mohm) goes directly to the multimeter chip. My guess is that the input protection is a single transistor (Q1), it looks like the 5 diodes (D3..D7) is used for coding range switch to multimeter chip and the two other diodes (D1 & D2) may be rectifier circuit for AC measurement where VR2 is used to adjust it with.
The multimeter chip (IC1 CS7721) handles everything in the meter.

Conclusion

The meter is specified at 600V, but the ranges can only handle 250V in overload.

The meter has about the expected functions for a pocket meter without any current ranges. There is a few problematic areas with it: Range switch must be carefully placed in the correct position it do not snap into position, buzzer is difficult to hear, duty cycle is low performance and the lowest capacity range is not completely reliable.

Notes

How do I review a DMM
More DMM reviews

mrheosuper · 2018-04-09T14:59:03.000Z

This is a small pocket DMM with voltage, current, frequency, ohms and capacity.

well, i think u made mistake here

HKJ · 2018-04-09T15:11:57.000Z

mrheosuper:

This is a small pocket DMM with voltage, current, frequency, ohms and capacity.

well, i think u made mistake here

Looks like it, I have fixed it. Thanks.

Andrew_Debbie · 2018-04-09T15:15:01.000Z

I’m glad you bought that one so we don’t have to.

ick.

mrheosuper · 2018-04-09T15:16:11.000Z

HKJ:

mrheosuper:

This is a small pocket DMM with voltage, current, frequency, ohms and capacity.

well, i think u made mistake here

Looks like it, I have fixed it. Thanks.

Do you know any pocket DMM like this one but has current range( not big, about uA to about 500ma), sometime i need to measure small current and my clamp is not good for that

HKJ · 2018-04-09T15:18:27.000Z

mrheosuper:

Do you know any pocket DMM like this one but has current range( not big, about uA to about 500ma), sometime i need to measure small current and my clamp is not good for that

Uni-T I have a review prepared.

mrheosuper · 2018-04-09T15:50:05.000Z

HKJ:

mrheosuper:

Do you know any pocket DMM like this one but has current range( not big, about uA to about 500ma), sometime i need to measure small current and my clamp is not good for that

Uni-T I have a review prepared.

Can you give me its name, thks

HKJ · 2018-04-09T15:54:34.000Z

mrheosuper:

HKJ:

mrheosuper:

Do you know any pocket DMM like this one but has current range( not big, about uA to about 500ma), sometime i need to measure small current and my clamp is not good for that

Uni-T I have a review prepared.

Can you give me its name, thks

UT120C

Terry_Oregon · 2018-04-09T19:44:27.000Z

190uF takes about 40 seconds to measure.

Really? Not a typo? What does the display show during those forty seconds? Some people would just give-up, thinking something was wrong. Holding leads on a cap for forty seconds would be rather fatiguing, no wonder the displayed values would vary.

HKJ · 2018-04-09T20:13:27.000Z

Terry Oregon:

190uF takes about 40 seconds to measure.

Really? Not a typo? What does the display show during those forty seconds? Some people would just give-up, thinking something was wrong. Holding leads on a cap for forty seconds would be rather fatiguing, no wonder the displayed values would vary.

I just did a test again:
It stated by showing 0.070nF, then 14.89nF and after 45 seconds (this time) it showed 193.3uF. You basically have to know about what value you expect.
I have also started testing with a 10uF film capacitor (after I have made an electronic AC switch*), it only takes 3.8second to measure that.

Generally electrolytic capacitors are slower to test than film/ceramic capacitors and large capacitors are really slow. Time will, of course, vary between different meters and being so slow with 190uF is not very good, some meters can measure 70000uF in considerable less time.

*That switch makes it possible to measure shorter time (milliseconds to a few seconds) much more precise.

Terry_Oregon · 2018-04-09T20:29:25.000Z

Thanks for the clarification. Not that I've used a LOT of capacitance meters over my career (one 4-lead, one dedicated two lead, and various Flukes), I've never seen a meter showing the value ramping up, seems like an odd (cheap) way to do it. I've only seen the final value (only) displayed.

Have you seen this in other cheap DMMs?

HKJ · 2018-04-09T20:39:17.000Z

Terry Oregon:

Have you seen this in other cheap DMMs?

Yes, but I have not kept track of what meters do it. Generally you will know what value you are expecting and just want to know if the capacitor is still working. .

Andrew_Debbie · 2018-04-10T06:37:55.000Z

The MS8216 is $6.66 on Banggood. Implied meanings aside (very different in Chinese) there are better choices in the under $10 price range.

The Aneng 8202 is about $16 today but coupons can get it much lower. I paid £6.78 ($9.50) 6,200 count, can measure current and the leads aren’t soldered in. You don’t have to take it apart to change the batteries . . .

HKJ · 2018-04-10T06:47:04.000Z

Andrew_Debbie:

the leads aren’t soldered in.

Soldered leads are not necessarily bad for these small meters.
If the lead breaks where it goes into the meter, it is usual a very simple reparation. A lead with a molded plug is not as simple to fix.