DMM Fluke 17B+

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This is a Fluke DMM designed to be sold in China, i.e. I doubt any authorized Fluke dealer in the EU/USA will have it, but due to all the Chinese shops selling directly to EU/USA it is very easy to buy and considerable cheaper than a regular Fluke DMM.

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The meter arrived in a yellow Fluke box with Chinese writing (I bought it from a German seller on Ebay).

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It included the DMM, a pair of probes, a thermocoupler and a manual in Chinese.

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The probes has removable tip covers.

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The probes are the Fluke TL75 model.

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The probes are rated for 10A, and CAT II, CAT III, CAT IV

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The thermocoupler looks like a good construction and is marked Fluke.

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Display

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The above picture shows all the segments on the display.

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Typical display during usage, it will show the number and what measurement is selected.

Warning

There is a red warning light, this will turn on when DC or AC voltage is above 30V or when selecting "Hz %" in a voltage range (Because it is impossible to see the actual voltage). The LCD display will also show a lightning symbol.



Functions

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Buttons:
Rotary switch:

Input

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Measurements
1uF

A look at the capacity measurement waveform.

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Tear down

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6 long screws and the back could be removed.

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This DMM has real input protection. The two fuses are 1000V and HRC, i.e. they can both break 1000's of amperes.
The mA uA range has a diode bridge (CR9) and a diode (CR5) to protect the shunt until the fuse blows. The mA current shut is R21 (1ohm) and the uA shut is R25 (100ohm).

There is also a 10MOhm resistor (R63, R65, R104, R105).

The chip (U8) near the input terminals is probably for measuring temperature and used for compensation when using thermocouplers.
The current output for ohm and capacity has a lot of protection: A big resistor (R20), some MOVs (RV1, Rv2, RV3) and PTC (RT1).

There is a EEPROM for calibration data (U6:24AA024H). It looks like they are low on pins for the main chip (U1), there is a chip (U7:74HC148) to encode 8 switch positions onto 3 bits. The other HC148 (U2) is probably doing something similar, maybe with the switches?

The slots are used for plastic shields, this greatly increases the isolation distance.

The group of 6 golden points near the two square battery connections are for calibration, there is a hole in the bottom of the battery compartment for access.

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A input resistor is placed on this side, it is build from 7 resistors (R2, R8, R14, R24, R2?, R29, R37: All 143kohm).

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The circuit board is 4 layer, here I have added some light from behind, this makes it possible to see some of the buried traces.

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And from the other side.



Conclusion

This is a Fluke meter made for the Chinese market, this means Fluke do not sell it in Europe or USA, but it is possible to buy from Ebay. It has good input protection, making it safe to use within its marked CAT rating. For a Fluke this DMM is fairly cheap, but that do not make it a cheap meter.

It has the usual ranges for a good DMM, but nothing extra.




Notes

It is possible to download a English manual from Fluke.

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