Mastech MS8209 multimeter comments

[Tomi Engdahl]

Mastech MS8209 is an amazing multimeter. It has all feature that regular multimeter has plus sound level meter, lux meter, thermometer and humidity meter.

The things I liked:
- practically all the necessary multimeter measurements including frequency and capacitance measurements
- good mechanical consruction, convient size and durable
- the test leads that came with the meter are good quality
- supports relative measurements
- has data hold
- has backlight on display
- auto power-off
- autoranging
- beeper is nice when testing wires
- frequency and dutu cycle measurements
- sound level and light level measurements are sometimes useful
- the meter came with a carrying case than can hold the meter and wires

Things that could be better:
- The specifications talk about 35-100 dB measurement range, not particarly good on low volumes, useable measurement range more like 65-100 dB, absolute accuracy not the best possible (can have 4 dB error), no specifications on dB meter frequency response
- the first unit I received measured temperatures wrongly (5 degress error at 23 degrees room temperature), I got it replaced with a new one that worked well on this
- capacitance measurement is quite slow to measure some values (compared to dedicated capacitance meter)
- meter measured well square wave signals, put had some problems in always detecting frequency of short pulse streams (for example measure HSYNC frequency measurements did nto work on all PC video sytems I tried this)
- not the most accurate meter
- diode measuring voltage limited to around 1.5V max, works for testing normal diodes, but not suitable for testing LEDs


Very nice multimeter that does lots of things that you normally don't have around on the field or laboratory. Very nice multimeter with lots of features at very attractive price. Does not replace expensive meters in case you need very accurate results, but gives you useful indication of many things you don't usually have a special instrument around.


Where I bought this:
Suomen huoltopalvelu Oy
http://www.shp.fi/

Price: Market price is around 100 US dollars or 85 Euros

Product information page: http://www.multimeterwarehouse.com/MS8209.htm

Where you can buy this product:
Google search http://www.google.fi/search?q=MS8209&ie=UTF-8&hl=fi&lr= gives you many very many hits


Things that woudl be nice to have / make this even better:
- If I could just have this meter with just clamp-on current probe built int, non-contact IR thermometer, inductance measurements, relative dB measurements on AC signals and tru RM on this, this would have all would like to have from an ideal multimeter!
- some more accuracy would be nice
- a PC interface would be nice add-on

[Tomi Engdahl]

I forgot to add link to the meter manufacturer web site. It is at http://www.p-mastech.com/

[Tomi Engdahl]

MS809 Product image from http://www.rpelectronics.com/Data/MS8209.JPG

[HWman]

MS8209 multimeter was also tested at
http://www.devhardware.com/c/a/Mobile-D ... er-Review/

In short this test lists:

Pros
Rugged/rubberized sturdy design
High quality test leads
Accurate sensors all around
Backlight
5-in-1 concept
Built in stand/prop
Included carrying case

Cons
Steep price if all features aren't needed
Thermocouple could be of higher quality
Scratch that shouldn't have passed Q.C.
Hard to find fuse used instead of a more common one
Horribly translated manual

"After all, these people might be inclined to purchase instruments that do all the things the 5-in-1 does separately. A digital light sensor=$60+, digital humidity sensor=$30+, digital temp sensor=$10, digital decibel sensor $100+, digital multimeter=$15+...totaling just the first three equals the price of the MS8209."

"For the average enthusiast though, this might be a bit of overkill. Most people will have no use for a humidity sensor or a light sensor or even a decibel sensor beyond maybe one or two quick tasks,"

One comment: The meter uses F 500 mA 250V 4x20 mm fuse. This fuse is very commonly available in Europe for verymanu sources.. Maybe it is harder to get in USA.

There are even images what this meter looks inside at
http://www.devhardware.com/c/a/Mobile-D ... -Review/4/



The picture shows that there is quite many potentiometers in there...

[Tomi Engdahl]

There different comments on the measurements with the multimeter if this is a true RMS multimeter or not.

According the manual I have the manual says on AC measurement ranges: "Response: Calibrated in the rms of sine wave"

On the other hand web page http://www.radios4you.com/dmm-5in1.html advertises this multimeter as "MASTECH MS8209 DMM 5 IN 1 TRUE RMS 4 1/2 DIGITS BACKLIT DMM"

And http://www.multimeterwarehouse.com/MS8209.htm says
"ACV:0V/4V/40V/400V/60V +- 1.0% (True RMS)".

And also http://www.electronicsparadise.com/t/Th ... 64OZ1K.htm

There are also pages whigh do not mention true RMS. And the manual does not tell about it.

Which one of those is true?

It is well possible that the manual is wrong or the advertisement on those web sites are wrong. Or have the technical specifiations of this meter suddenly changed over the time?

[Tomi Engdahl]

Does anyone have any calibration documentation or service manual for MS8209 multimeter ?

It seems that the caliration of the environmental measurements is not the most accurate in this particular meter. My meter unit did not seem to measure the lowest dB numbers well.. Every time the reading seems to 60 dB or higher (my environments could not be that noisy, based on measurements with other meters).

I have got some calibration information from one person who has opened this same multimeter sold with Lexa brand name (Mastech makes multimeters for other brands, I know that meters made by them are sold for example with Velleman, Biltema, and many other brands...)
Anyway that source told that trimmer potentiometers VR5 and VR6 control the temperature measurement. And that VR7 would control the reading you get in darkness with Lux meter...

I would be interrested in the calibation of the dB scale.
I have access to another dB meter so I could propably calibrate is to be more accurate at low sound levels than what it is now...
But I need the instructions where are controls for this range so that I don't mess up with the other controls on the meter, because other ranges seem to be accurate.

[Guest]

Hi there!
I just contacted Mastech corp. directly and asked them to purchase me calibration instructions of MS8209. I will inform group if they prowide any information about calibration of multimeter.
Another important notification:
Contact surfaces of turnswitch on pcb-board are wery bad quality.
Specially two inner circles witch have very small contact sectors will easily make short circuits between eachother! For example in my multimeter (witch I got for free because it was broken!) there was small bridges between contacts and most of the multimeters functions were malfunctioning! Repairing was easy task by using precicion knife to scratch shortcircuits away from pcb-board! With careful calibration I expect to have a useful "real multimeter" for everyday use!
/Esa

[Hans van Kempen]

For all out there the calibration procedure which Mastech supplies on E-Mail request.


CALIBRATION OF THE MS8209 DIGITAL MULTIMETER

DISASSEMBLY: Remove the two Philips-head screws from the bottom of the case and
carefully lift the back off, bottom (screw holes) first.
NOTE: Adjust the trimpots very gently to avoid damaging these small components!
Test leads should be initially inserted into the COM (black) and V?Hz (red) jacks.

1. DC VOLTAGE ADJUSTMENT:
(1) Set the rotary switch to the V AUTO range position.
(2) Connect the test leads to a known DC voltage less than 200 mV. Adjust variable
resistor VR1 (10k?) to read correctly on the LCD display.
(3) Confirm the adjustment by stepping the RANGE button through its other
settings, noting the readings.

2. AC VOLTAGE ADJUSTMENT:
(1) With the rotary switch still in the V range position, press the FUNC. button
to select AUTO AC measurement.
(2) Connect the test leads to a known AC voltage less than 2 V @ 60Hz. Adjust
variable resistor VR2 (5k?) to read correctly on the LCD display.
(3) Confirm the adjustment by connecting the test leads to standard AC line voltage
and reading the display.

3. DC CURRENT ADJUSTMENT:
(1) Set the rotary switch to the 400mA position.
(2) Connect the test leads in line with a known DC current near 10mA. Adjust
variable resistor VR3 (5k?) to read correctly on the LCD display.
(3) Confirm the adjustment by connecting the test leads to a known higher current
of less than 400 mA and reading the display.

4. CAPACITANCE ADJUSTMENT:
(1) Set the rotary switch to the ? position.
(2) Press the FUNC. button to enter the measurement.
(3) Connect the test leads to a standard capacitance near 100nF. Adjust the
variable resistor VR3 (5k?) to read correctly on the LCD display.
(4) Confirm the adjustment by connecting the test leads to higher known
capacitances and reading the display.

5. TEMPERATURE ADJUSTMENT:
(1) Move the red test lead to the mA C jack.
(2) Set the rotary switch to the 0.1 C position.
(3) To adjust the normal indoor temperature (20 C), connect the test leads to a
standard 0.798 mV DC source and adjust the variable resistor VR5 (5K?) to
read 020.0 on the LCD display.
(4) Set the rotary switch to the 1C position.
(5) To adjust the high temperature (400 C), connect the test leads to a standard
DCV 16.40mV source and adjust the variable resistor VR6 (10k?) to read 0420
on the LCD display.
(6) Refer to the following chart for voltages vs. temperature; if they do not conform,
repeat steps 3 and 5.

Input Volt (mV)
-0.777
0
0.798
4.095
8.137
12.207
16.40
20.64
29.128
Temp(C)
-20
0
20
100
200
300
400
500
700

6. HUMIDITY ADJUSTMENT:
(1) Set the rotary switch to the %RH position.
(2) To adjust low humidity, place the meter in a test box set to 50%RH and adjust
the variable resistor VR11 (10K?) to read 050.0 on the LCD display.
(3) To adjust high humidity, place the meter in a test box set to 90%RH and adjust
the variable resistor VR10 (5K?) to read 090.0 on the LCD display.
(4) Repeat steps two and step three if necessary to conform accurately.

7. SOUND LEVEL (dB) ADJUSTMENT:
(1) Set the rotary switch to the dB position.
(2) To adjust the low sound level (dB), place the meter in a test box set to 60 dB
and adjust the variable resistor VR13 (2K?) to read 060.0 on the LCD display.
(3) To adjust the high sound level (dB), place the meter in a test box set to 90 dB
and adjust the variable resistor VR12 (500?) to read 090.0 on the LCD display.
(4) Repeat steps two and step three if necessary to conform accurately.

8. ILLUMINANCE (Lux) ADJUSTMENT:
(1) Set the rotary switch to the Lux position.
(2) Place the meter in a test box set at 1000Lux and adjust the variable resistor
VR8 (2K?) to read 1000 on the LCD display.
(3) Set the rotary switch to the X10Lux range position and adjust the variable
resistor VR9 (500?) to read 0100 on the LCD display.

NOTE: 10A, Hz, resistance and diode ranges do not need adjustment.

[Visitor]

It seems that some multimeter shops have seen that the calibration of those MS8209 multimeters when they come from factory is not very accurate. For example web page http://www.grove-ent.com/MS8209.html says:
"NOTE: There is variance in accuracy among units. A detailed calibration procedure is included for competent technicians who need improved accuracy."

[Tomi Engdahl]

That Mastech MS8209 calibration instructions posted by Hans van Kempen is pretty close to the calibration instructions I got from one other source. The procedure is the same, but the wording is liglty different.

When calibrating with a friend few of those multimeters we found out that the calivration instrutions given are not completely accurate.

For example the R3 is marked in both instructions (the one posted here and what I received from other source) for DC current and capacitance range. This is definately not right. R4 is for capacitance range adjusting (I tested that) and R3 for DC current.

The adjustment controld and their function:

VR1 DC voltage
VR2 AC voltage
VR3 DC current
VR4 Capacitance (based on own testing)
VR5 Temperature capacitance
VR6 Temperature capacitance
VR7 Lighting range zero adjustment (based on own testing)
VR8 Lighting level lux range
VR9 Lighting level X10Lux range
VR10 humidity
VR11 humidity
VR12 dB range
VR13 dB range

[dolphin]

I cleaned up those calibration instructions, and corrected the errors (including one not mentioned here)

For those of you who don't know; thermocouple readings are always read as a voltage that represents the DIFFERENCE in temperature between the target and the test instrument. Then, locally measured temperature is added to the reading for display. So when you short the leads in the C ranges, you get an ambient reading only. I've corrected the instructions to reflect this.

------------------

CALIBRATION OF THE MS8209 DIGITAL MULTIMETER


DISASSEMBLY: Remove the two Philips-head screws from the bottom of the case and carefully lift the back off, bottom (screw holes) first. NOTE: Adjust the trimpots very gently to avoid damaging these small components! Test leads should be initially inserted into the COM (black) and V/ohm/Hz (red) jacks.


1. DC VOLTAGE ADJUSTMENT:

(1) Set the rotary switch to the V AUTO range position.

(2) Connect the test leads to a known DC voltage less than 200 mV. Adjust variable resistor VR1 (10K) to read correctly on the LCD display.

(3) Confirm the adjustment by stepping the RANGE button through its other settings, noting the readings.



2. AC VOLTAGE ADJUSTMENT:

(1) With the rotary switch still in the V range position, press the FUNC. button to select AUTO AC measurement.

(2) Connect the test leads to a known AC voltage less than 2 V @ 60Hz. Adjust variable resistor VR2 (5K) to read correctly on the LCD display.

(3) Confirm the adjustment by connecting the test leads to standard AC line voltage and reading the display.



3. DC CURRENT ADJUSTMENT:

(1) Set the rotary switch to the 400mA position.

(2) Connect the test leads in line with a known DC current near 10mA. Adjust variable resistor VR3 (5K) to read correctly on the LCD display.

(3) Confirm the adjustment by connecting the test leads to a known higher current of less than 400 mA and reading the display.



4. CAPACITANCE ADJUSTMENT:

(1) Set the rotary switch to the ohms/cap/diode/continuity position.

(2) Press the FUNC. button to enter the measurement.

(3) Connect the test leads to a standard capacitance near 100nF. Adjust the variable resistor VR4 (5K) to read correctly on the LCD display.

(4) Confirm the adjustment by connecting the test leads to higher known capacitances and reading the display.



5. TEMPERATURE ADJUSTMENT:

(1) Move the red test lead to the mA/C jack.

(2) Set the rotary switch to the 0.1 C position.

(3) To adjust the low temperature range, connect the test leads to a standard 0.798 mV DC source and adjust the variable resistor VR5 (5K) to read 020.0 (plus actual indoor temperature) on the LCD display. When the leads are shorted out, the actual ambient temperature should be displayed.

(4) Set the rotary switch to the 1C position.

(5) To adjust the high temperature (400 C), connect the test leads to a standard DCV 16.40mV source and adjust the variable resistor VR6 (10K) to read 0400 (plus actual indoor temperature) on the LCD display.

(6) Refer to the following chart for voltages vs. temperature; if they do not conform, repeat steps 3 and 5.



Input Volt (mV) Temp(C) (add ambient to all readings!)


-0.777 -20

0 0

0.798 20

4.095 100

8.137 200

12.207 300

16.40 400

20.64 500

29.128 700





6. HUMIDITY ADJUSTMENT:

(1) Set the rotary switch to the %RH position.

(2) To adjust low humidity, place the meter in a test box set to 50%RH and adjust the variable resistor VR11 (10K) to read 050.0 on the LCD display.

(3) To adjust high humidity, place the meter in a test box set to 90%RH and adjust the variable resistor VR10 (5K) to read 090.0 on the LCD display.

(4) Repeat steps two and step three if necessary to conform accurately.



7. SOUND LEVEL (dB) ADJUSTMENT:

(1) Set the rotary switch to the dB position.

(2) To adjust the low sound level (dB), place the meter in a test box set to 60 dB and adjust the variable resistor VR13 (2K) to read 060.0 on the LCD display.

(3) To adjust the high sound level (dB), place the meter in a test box set to 90 dB and adjust the variable resistor VR12 (500) to read 090.0 on the LCD display.

(4) Repeat steps two and step three if necessary to conform accurately.



8. ILLUMINANCE (Lux) ADJUSTMENT:

(1) Set the rotary switch to the Lux position.

(2) In a dark place, adjust VR7 for 0 in the 1000 Lux range.

(3) Place the meter in a test box set at 1000 Lux and adjust the variable resistor VR8 (2K) to read 1000 on the LCD display.

(4) Set the rotary switch to the X10Lux range position and adjust the variable resistor VR9 (500) to read 0100 on the LCD display.



NOTE: 10A, Hz, resistance and diode ranges do not need adjustment.