Author Topic: If Brymen BM869s is cheaper and as good, why people would still buy Fluke?  (Read 129931 times)

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Offline markone

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There's this thing called the laws of physics. The output rails of an ATX PSU have massive amounts of capacitance on them. This means that the output voltage simply can't change that fast.

Dunno what you mean with "massive amounts of capacitance" but if you take a look to modern topolopy ATX PSUs where a single 12V bar supply several very high frequency DC/DC converters to provide +5V, +3V3 and so on, you can find ceramic capacitor and/or small low ESR electrolytic in output stages, sure not "massive" values (take a look to Corsair AX series, for instance).

The voltage ripple/drop that you can find on those outputs under medium/heavy load could be quite nasty and very far to be monitored with 87V peak capabilities, an utterly wrong instrument to keep in account in this scenario.

I could agree that with linear PSU it would come in handy in absence of a DSO, but nowaday everyone has at least one  ;D

Just out of curiosity, have you ever used an 87V?

I used a Fluke 189 for several years for ordinary task, the lab where i was before (yes, the employer was paying the bill) had a bunch of them, some failed, mine lost buzzer function after a while.

Despite so i liked it, but you could understand why i do not consider them "foolproof".

What if my 869S fails out of warranty ?

Simple, i'll buy another one (or something else, if available), still saving money against a single Fluke 87V and taking advantage with :

- double thermocouple reading
- double display
- additional resolution digit
- pc interface

all things that i care for .
But considering that my piece of cr@p V&A VA38 still works after six years of continuos job, with its creaky & scratchy case, i will dare to say that this one has the potential to last waaay more.

I do not have any personal interest to push BRYMEN products, i only think that for the price they are a smart choice for hobbiest, while professionals and companies, being able to deduct equipments purchases from taxes, will continue to be the preferred Fluke's customers.
« Last Edit: March 01, 2016, 02:02:48 am by markone »
 

Offline mos6502

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No, you have capacitances of several thousand uF in every PC power supply. The Corsair AX you mentioned?



What do you think the big cylindrical things are on the right side?  ;)

And don't forget that the capacitances on PC power rails are not just one the ouputs, but also on the inputs. Motherboards and graphics cards have a giant number of caps at the input.

My point still stands, the 87V can reliably measure the quality of AC and DC power supplies and detect faults using its Peak Min/Max mode.

One more interesting difference:

Fluke 87V: Operating temperature –20°C to + 55°C

Brymen BM869s: Operating Temperature: 0ºC to 45ºC

Even if you're a hobbyist, the Fluke is still a better choice. The 4 times longer battery life, better diode test (forget trying to test HV diodes with the Brymen), much faster peak detect and lack of annoying backlight timer all still work in your favor. And if you buy a used one, it's about the same price as the Brymen 869s. Used Fluke 87Vs are all over eBay, used Brymens on the other hand, none.

Look, I'm not saying the 869s is a bad meter, but if I could only have one meter, it would definitely be the 87V. The Brymen would be interesting to have as a second or third meter, though.
for(;;);
 

Offline markone

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No, you have capacitances of several thousand uF in every PC power supply. The Corsair AX you mentioned?



What do you think the big cylindrical things are on the right side?  ;)

 :-DD

Not sure if serious.

Think at least twice before to post, those are DC BUS capacitors just after PFC stage :palm:

Secondary rails (5V, 3V3) DC/DC converters are on the right side of the picture on vertical PCB boards, including the one carrying output connectors, they are working at hundreds of thousands of Hz, please find those alleged "thousand uF" capacitors on their outputs and show us their images.

My point still stands, the 87V can reliably measure the quality of AC and DC power supplies and detect faults using its Peak Min/Max mode.

Good luck.

Thanks to this post your perceived competence on switched power supply dropped near zero.
 

Offline mos6502

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No, you have capacitances of several thousand uF in every PC power supply. The Corsair AX you mentioned?



What do you think the big cylindrical things are on the right side?  ;)

 :-DD

Not sure if serious.

Think at least twice before to post, those are DC BUS capacitors just after PFC stage :palm:
Secondary rails (5V, 3V3) DC/DC converters are on the right side of the picture on vertical PCB boards, including the one carrying output connectors, they are working at hundreds of thousands of Hz, please find those alleged "thousand uF" capacitors on their outputs and show us their images.



So, you're saying, those are 380V capacitors?  :-DD

My point still stands, the 87V can reliably measure the quality of AC and DC power supplies and detect faults using its Peak Min/Max mode.

Good luck.

Thanks to this post your perceived competence on switched power supply dropped near zero.

Moderator remove offensive text
« Last Edit: March 02, 2016, 07:07:56 am by Simon »
for(;;);
 

Offline HackedFridgeMagnet

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Thanks to this post your perceived competence on switched power supply dropped near zero.

Please no flame war. Try to understand what the other is saying, it is not that hard.


Personally a scope would be my preference, and I really like my Brymen meters.

... and the accompanying mouth.
You should retract that statement. Else I will ask a moderator to.
 

Offline EEVblog

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You should retract that statement. Else I will ask a moderator to.

How about everyone just calm down and keep it technical?
 

Offline Wytnucls

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While it is true that peak detection is easier with an oscilloscope, if that feature is implemented on a multimeter, make it worthwhile or don't bother. 800uS doesn't cut the mustard, when the industry average is 250uS for a repetitive transient (Fluke, Keysight, Hioki). Brymen is clearly the laggard in that respect (Uni-T does 10uS and it works). Gossen doesn't bother at all with that feature, except on the Energy (400uS).
« Last Edit: March 02, 2016, 03:47:47 am by Wytnucls »
 

Offline jwm_

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1 Gohm? That's insane. What are the practical applications for this?

1Gohm is considered low impedance for many applications, good meters have 200 teraohm input impedances[1].

Even keithleys older ones you can find cheaply on ebay have 10^14 ohm input impedance.

It becomes important any time you are working with very high voltages, very high resistances, or very low currents, or electrostatics.

[1] http://www.tek.com/low-level-sensitive-and-specialty-instruments/high-resistance-low-current-electrometers-series-6500-

Offline Tim F

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As long as we're talking Fluke and Brymen, anyone want to weigh-in with any experience with, or thoughts on, the Fluke 115 vs. the Brymen 257s?  [...] Brymen seems to be equivalent or wins on most specs.
I can't speak for the BM257S however I have experience with numerous Fluke 115 which must be at least 5+ years old, used and abused at a university and still agree within 1digit of my own 87Vs (2013 and 2015 mfg dates). It really does build confidence for the Fluke brand when you see stuff like that.

I actually really like the 115 and think it is actually a better 'every day' meter than an 87V. The range switch can't be beat for one handed operation. That said, the 115 doesn't have a milliamps or microamps range which is a problem if you need accurate <100mA measurements. BM257s does have those ranges.

edit:oops really old thread, someone might still find this useful though.

The killer features of the 87V:

- 250us peak min/max. It's hard to convey in words how awesome this feature is. This means the meter can replace an oscilloscope in many scenarios.
- 8V diode test. 'Nuff said. No other meter does this.
- No backlight timer. Once you turn it on, it stays on. This shows a deeper philosophy. The Fluke engineers assume that the users are people who know what they're doing, not senile old women.

Also:


I haven't done any conclusive testing, but what seems to happen in experience with the 87V is that when you enable hi-res you are changing the entire operation of the ADC from 6000 count to 20000 count mode. It is not simply rounding a 20000 count reading to 6000 count. The reason I believe this is the case is because if you measure a voltage which produces the same count on both low res and high res modes, you can get different readings. E.g. you measure a stable 5.000V on low res, then you may get a stable 4.999 or 5.001 by enabling hi-res.
So in certain situations (e.g. measuring 5.000V) it may actually be preferable to be in the 6000 count mode because you achieve higher dynamic range on the ADC and probably lower noise.
« Last Edit: March 02, 2016, 05:10:56 am by Tim F »
 

Offline joeqsmith

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Used Fluke 87Vs are all over eBay, used Brymens on the other hand, none.

That does not surprise me!  :-DD
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline 3141592

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I wonder if you really wacthed those videos, the truth is there, no weird things with high res mode engaged, the BRYMEN has one digit more than 87V and it's working good for tendency monitoring, you have to accept it.

Very limited real-world use. Say I remove the charge current from a battery. I know what's going to happen. The voltage is going to drop slowly. It's not going to go up. I don't need a meter to tell me that. If I want to measure how fast it drops, 4 1/2 digits are plenty enough.

I don't know why no one ever mentions other uses for the resolution other than watching a battery discharge, but the 500k counts mode sees regular use on my BM857. For once, it provides µV resolution on the mV range, and it worked great for monitoring the output of Wheatstone bridges for example. I also use the meter fairly often to match resistors, although it's only 50k counts in that mode. I have never had a need for the crest/peak function though. So I guess we can agree that different people want different features from their DMM.

No, it clearly shows the engineers didn't think the design through. Either that, or they just didn't gave a shit. Wait, maybe that's the reason they design a backlight that makes an annoying high pitched sound. How can you rely on a meter that does weird, unexpected things?

Uh, what? Not rounding introduces a maximum error of 0.9 count or ~.002% FS on a meter that has a .02% + 2 counts DC accuracy. It may not be the proper way to handle the 500k/50k conversion, but it's impact on accuracy is negligible. The backlight noise issue is also blown way out of proportion, as it's a minor annoyance at most and has no impact on performance. If you think these show how Brymen is uncapable, how do you explain away Fluke's blunders, with some of them being way worse than this?
 

Offline blacksheeplogic

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If you think these show how Brymen is uncapable, how do you explain away Fluke's blunders, with some of them being way worse than this?

They fix and recall their meters.
 

Offline Lightages

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I am trying to stay out of this fan boy fight, but.....

Both companies and meters have their benefits and draw backs. One can pick the ONE unique thing that matters to you and make that the most important thing if you want. That does not make it the most important thing to others just because you said so. Each has their own preferences. Some people prefer a longer warranty, some prefer a lower price. Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.
 

Offline markone

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I don't know why no one ever mentions other uses for the resolution other than watching a battery discharge, but the 500k counts mode sees regular use on my BM857. For once, it provides µV resolution on the mV range, and it worked great for monitoring the output of Wheatstone bridges for example. I also use the meter fairly often to match resistors, although it's only 50k counts in that mode. I have never had a need for the crest/peak function though. So I guess we can agree that different people want different features from their DMM.

Uh, what? Not rounding introduces a maximum error of 0.9 count or ~.002% FS on a meter that has a .02% + 2 counts DC accuracy. It may not be the proper way to handle the 500k/50k conversion, but it's impact on accuracy is negligible. The backlight noise issue is also blown way out of proportion, as it's a minor annoyance at most and has no impact on performance. If you think these show how Brymen is uncapable, how do you explain away Fluke's blunders, with some of them being way worse than this?

+1  :-+
 

Offline mos6502

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I wonder if you really wacthed those videos, the truth is there, no weird things with high res mode engaged, the BRYMEN has one digit more than 87V and it's working good for tendency monitoring, you have to accept it.

Very limited real-world use. Say I remove the charge current from a battery. I know what's going to happen. The voltage is going to drop slowly. It's not going to go up. I don't need a meter to tell me that. If I want to measure how fast it drops, 4 1/2 digits are plenty enough.

I don't know why no one ever mentions other uses for the resolution other than watching a battery discharge, but the 500k counts mode sees regular use on my BM857. For once, it provides µV resolution on the mV range, and it worked great for monitoring the output of Wheatstone bridges for example. I also use the meter fairly often to match resistors, although it's only 50k counts in that mode. I have never had a need for the crest/peak function though. So I guess we can agree that different people want different features from their DMM.

The reason why no one ever mentions other uses is because resolution is not accuracy. The accuracy is specced at 0.02% +-2 digits, the digits referring to the 50.000 count reading.  Example: you're measuring a 5.00000V precision reference. The 869s could be displaying anywhere from 4.99880 to 5.00120. Those extra digits are nothing more than a gimmick.

And matching resistors? Seriously? Let's say the contact resistance of the probes will introduce an error of 100 milliohms (which would be a very good value). That's 0.1% on a 10k resistor and 1% on a 1k resistor. A handheld multimeter is the wrong tool for the job. You need a bench multimeter or an LCR meter that allows for 4-wire measurements. Unless you don't care about a 0.1-1% error ... but then you might as well buy 0.1% or 1% resistors.

No, it clearly shows the engineers didn't think the design through. Either that, or they just didn't gave a shit. Wait, maybe that's the reason they design a backlight that makes an annoying high pitched sound. How can you rely on a meter that does weird, unexpected things?

Uh, what? Not rounding introduces a maximum error of 0.9 count or ~.002% FS on a meter that has a .02% + 2 counts DC accuracy. It may not be the proper way to handle the 500k/50k conversion, but it's impact on accuracy is negligible.

Exactly. The whole 500k count mode is a gimmick. They Brymen engineers knew it wouldn't matter if they implemented it properly or not - they could've simply left it off.
« Last Edit: March 02, 2016, 11:01:24 pm by mos6502 »
for(;;);
 

Offline mos6502

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I am trying to stay out of this fan boy fight, but.....

Both companies and meters have their benefits and draw backs. One can pick the ONE unique thing that matters to you and make that the most important thing if you want. That does not make it the most important thing to others just because you said so. Each has their own preferences. Some people prefer a longer warranty, some prefer a lower price. Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.

Except, saying it's personal preference is a meaningless statement. We're not talking about shirt colors. Why do you prefer one over the other? That is the question. So far, a lot of the rationale of the pro-Brymen crowd has been based on something other than fact.
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Offline wraper

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The reason why no one ever mentions other uses is because resolution is not accuracy. The accuracy is specced at 0.02% +-2 digits, the digits referring to the 50.000 count reading.  Example: you're measuring a 5.00000V precision reference. The 869s could be displaying anywhere from 4.99880 to 5.00120. Those extra digits are nothing more than a gimmick.
It is not a gimmick. Yes, there is difference between accuracy and resolution but you do not always need that absolutely accurate number. Actually you might not care if it shows 4.99880 or 5.00120 but you might care if it goes from 4.99880 to 4.99889. Therefore you know that there was a voltage change despite that big absolute background voltage. If you don't have that last digit, you don't know if that change happened at all.
 

Offline wraper

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I am trying to stay out of this fan boy fight, but.....

Both companies and meters have their benefits and draw backs. One can pick the ONE unique thing that matters to you and make that the most important thing if you want. That does not make it the most important thing to others just because you said so. Each has their own preferences. Some people prefer a longer warranty, some prefer a lower price. Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.

Except, saying it's personal preference is a meaningless statement. We're not talking about shirt colors. Why do you prefer one over the other? That is the question. So far, a lot of the rationale of the pro-Brymen crowd has been based on something other than fact.
You forgot to mention that all of those 6.5+ digit Fluke and Keysight meters are a gimmick too. Because, obviously, they have those "useless" digits too.
 

Offline Lightages

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I am trying to stay out of this fan boy fight, but.....

Both companies and meters have their benefits and draw backs. One can pick the ONE unique thing that matters to you and make that the most important thing if you want. That does not make it the most important thing to others just because you said so. Each has their own preferences. Some people prefer a longer warranty, some prefer a lower price. Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.


Except, saying it's personal preference is a meaningless statement. We're not talking about shirt colors. Why do you prefer one over the other? That is the question. So far, a lot of the rationale of the pro-Brymen crowd has been based on something other than fact.

Obviously it is pointless to converse with you because you ignore what I have said and only count what you want as important, just as I asserted.
Quote
Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.

A lower price is fact. Some prefer a lower price. A higher accuracy for a lower price is a fact for Brymen. A higher CAT rating is a fact for Brymen. A lifetime warranty for Fluke is a fact for some. A well earned reputation is a fact for Fluke. There are others, but I feel I am wasting my time stating facts as they are ignored. Some people prefer some of these facts over others. Everything is a compromise. You obviously have your preferences and don't see that others can have their preferences that are valid for them, or are trolling. I don't know which is correct.
« Last Edit: March 02, 2016, 11:26:41 pm by Lightages »
 

Offline HackedFridgeMagnet

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A lifetime warranty for Fluke is a fact for some.
Lol.

I and I'm sure many others appreciate your efforts and even handedness, Mr Lightages. 
Continue to state the facts when the situation arises.
 

Offline TheSteve

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You buy a (used) Fluke over a Brymen because if you buy a good model at a fair price (such as an 87V) you can use it for 10 years and as long as you haven't killed it you can resell it for what you paid. Try that with a Brymen(or almost any other "B" brand.)
VE7FM
 

Offline Wytnucls

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Some factual reasons why someone may prefer a more expensive Fluke 87V:
Low burden voltage
Hi Z mode
High diode test voltage
Frequency trigger on +/- slope
Smoothing option on display
Backlight on/off switch with intensity control
Bargraph zoom mode
Peak Hold 250uS
Standard hold and auto Hold
Battery life 400 hours
High voltage warning on display
IP30 rating with 1 meter drop test
Long warranty period
Easy after sales service

« Last Edit: March 03, 2016, 12:20:35 am by Wytnucls »
 

Offline Lightages

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Quote
You buy a (used) Fluke over a Brymen because if you buy a good model at a fair price (such as an 87V) you can use it for 10 years and as long as you haven't killed it you can resell it for what you paid. Try that with a Brymen(or almost any other "B" brand.)

Really? You can buy a used Fluke and sell it for the same price 10 years later? Is that including inflation? I would love to see proof of this either way.
 

Offline TheSteve

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Quote
You buy a (used) Fluke over a Brymen because if you buy a good model at a fair price (such as an 87V) you can use it for 10 years and as long as you haven't killed it you can resell it for what you paid. Try that with a Brymen(or almost any other "B" brand.)

Really? You can buy a used Fluke and sell it for the same price 10 years later? Is that including inflation? I would love to see proof of this either way.

Perhaps I am the exception and not the rule but I bought a u lightly used 87 series I for a good deal on ebay 10 years ago, recently sold it for what I paid locally. Quality/brand name test equipment often holds its value very well. I then bought a used 87V for the same price I sold the series I for, just had to watch for a deal on craigslist.
VE7FM
 

Offline mos6502

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Some factual reasons why someone may prefer a more expensive Fluke 87V:
Low burden voltage
Hi Z mode
High diode test voltage
Frequency trigger on +/- slope
Smoothing option on display
Backlight on/off switch with intensity control
Bargraph zoom mode
Peak Hold 250uS
Standard hold and auto Hold
Battery life 400 hours
High voltage warning on display
IP30 rating with 1 meter drop test
Long warranty period
Easy after sales service

Larger operating temperature range -20 to +55C
Better resale value  :-+
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