Home Articles Downloads Forum Products Services EBME Expo Contact ☰
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 3 1 2 3
Joined: Apr 2005
Posts: 380
Laiq Offline OP
Sage
OP Offline
Sage
Joined: Apr 2005
Posts: 380
Dear all
I have arranged all the required LOAD RESISTANCEs, FLUKE RMS MULTIMETER & i have NEURODYNE DEMPSEY 443 ESU ANALYSER.
As one technician told me that i have to use PEARSON 411 CURRENT MONITOR for the measurement. But i dont have it nor it is available in PAKISTAN. So can i use my old NEURODYNE ESU ANALYSER instead..
Any suggestions or help in calibrating FX ESUs without current monitor. Any work around or improvisation to achieve it.
Waiting for quick & positive reply.
Thanks in advance.
Regards
LAIQ

Joined: Feb 2004
Posts: 14,815
Likes: 72
Super Hero
Offline
Super Hero
Joined: Feb 2004
Posts: 14,815
Likes: 72

That's the trouble with so much modern kit, Laiq ... the manuals place so many obstacles in the way of (what we might call) a "generic"* approach to testing.

All very well perhaps if you're based in a hospital, with only one line of ESU's to support. But what about those of us who may encounter various types, from various manufacturers, and of various vintage?

Well, one way would be to have to hand every bit of test equipment known to man ... but failing that, I would suggest reverting to "first principles".

In the case of ESU's (of any type) I would suggest the following approach with regards to Output:-

Waveforms across an appropriate load! And work up your own procedure(s), using whatever test equipment you have to hand, and retain good records (for comparison next time).

In theory, any decent ESU analyser should be able to be pressed into service. Those older ones are basically just heavy load resistors, after all (as are the later ones ... that's why they're so hefty)! And the one you've got there is a good old one, is it not?

With regards to testing the various "clever" (and some not so clever) return electrode circuits, with alarm trigger levels and such ... well you just have to improvise a bit there, I'm afraid.

Good luck, Mate. Be sure to let us know how you get on. smile

But what's the big deal about using this thing? "High currents transformed to pleasant scope input levels" ... there must be another way (because there always is)! If the manual only talks about current measurements (?), then that sounds like a return to good old Ohm's Law to me!

Lastly, check out this .pdf.

As an aside (if I may) many donated ESU's fail to get used due to what are often "minor" faults - and lack of local know-how when it comes to checking them out. Take a look at this.

* Shade-tree?


If you don't inspect ... don't expect.
Joined: Apr 2005
Posts: 380
Laiq Offline OP
Sage
OP Offline
Sage
Joined: Apr 2005
Posts: 380
Thanks GEOFF.
You know me, i dont follow company rules when i am stuck.
I was just asking for tips from PRO ENGINEERS like you..
I will try two strategies today as customer is pressing me hard.
Will share after this.
Thanks freind for your help.

Joined: Aug 2007
Posts: 306
Master
Offline
Master
Joined: Aug 2007
Posts: 306
Hi Laiq

The book actually says 'Current transformer (such as Pearson Model 411 or equivalent)' so you are ok as you are using an equivalent.

Can we take it that the equipment failed a test or had a component changed and you are calibrating. If it has failed the tests it is always a good move to check your connections to the test equipment are secure as you can get a little stray resistance that can push the values outside tolerance.

Saves you calibrating

Joined: Apr 2005
Posts: 380
Laiq Offline OP
Sage
OP Offline
Sage
Joined: Apr 2005
Posts: 380
Dear bcaslisle
Thanks for your reply.
Actually i have rcvd these machines with new RF boards & battery replaced. So they are like new & need calibration as error 212 coming.
Thanks to GEOFF for that pdf file. I am reading it, hopefully will get something out.
Thanks again.
If there is any alternate for Pearson 411 current monitor do let me know.

Joined: Apr 2005
Posts: 380
Laiq Offline OP
Sage
OP Offline
Sage
Joined: Apr 2005
Posts: 380
Another help needed..
As service manual is showing some values of current with specific load resistances for calibration.
Can some one explain that if lets say manual says CURRENT SENSE GAIN FOR BIPOLAR.
Resistance 10 ohms
Current reading from Pearson 411 CT to voltmeter should be 1.79A
==================
So as Pearson CT ratio is 10:1 (that is 0.1V/Amp)so should i have to divide or multiply the current value of ampere or is it actual ampere at 10ohms load.
Sorry as i still couldnot understand CURRENT MONITOR use.
Forgive me in advance.
Will wait for correction or guidance.

Joined: Aug 2007
Posts: 306
Master
Offline
Master
Joined: Aug 2007
Posts: 306
The bipolar cables are attached to the 10 ohm resistor and one is passed through the current monitor. When you transmit the induced current in the ring is 1.79A or 0.179V. (This is how I am reading it)

Joined: Oct 2007
Posts: 75
Adept
Offline
Adept
Joined: Oct 2007
Posts: 75
Vlab are very clear on what meter u are to use, a Fluke 8920A or a bc biomedical ESU-2050, you do get differant readings from a rms scope and other generic RMS meters including fluke,we have tried comparrisond against other meters has or fluke failed calabration, in the end, we got the ESU-2050, the pearson resistors you can get from RS, we have them called.

Joined: Apr 2005
Posts: 380
Laiq Offline OP
Sage
OP Offline
Sage
Joined: Apr 2005
Posts: 380
Thanks obiwan
I dont have time to buy from RS..
Brother can u guide me is there any way i can calibrate it using RMS watt meter or rms current meter.
Just let me know is this PEARSON CURRENT MONITOR reduces the output current from the generator or just isolates the generator from meter.
As its specs 0.1V/A shows that per 1 ampere current the output is 0.1V.. RIGHT or WRONG..
If i can get the real values of current for calibration steps i can do it. Thats why i am asking..
#1)Current sense gain factor
#2) Voltage sense gain factor
#3) Reactance gain factor
#4) ECON factor
Thanks in advance.

Joined: Apr 2005
Posts: 380
Laiq Offline OP
Sage
OP Offline
Sage
Joined: Apr 2005
Posts: 380
Hi guys
I am trying to calibrate it but 212 message is not going.
Also in step C5 the bipolar footswitch is not working.
Also in Step C1 the CUT DISPLAY SHOWING "4" not "5" as shown in manual.
If i shut down the unit & switch it on again same 212 message appearing. But manual showing that switch it off & then on the message will disappear. But not in case of my unit.
Please explain if some one can.
Waiting for quick reply.
Regards

Page 1 of 3 1 2 3

Moderated by  DaveC in Oz, RoJo 

Link Copied to Clipboard
Who's Online Now
1 members (daisizhou), 8,505 guests, and 293 robots.
Key: Admin, Global Mod, Mod
Newest Members
Pip Fox, Engzaki, MacMc, AraEmin, Edouardohaag
10,395 Registered Users
Forum Statistics
Forums26
Topics11,285
Posts74,589
Members10,395
Most Online69,877
Jul 17th, 2026
Powered by UBB.threads™ PHP Forum Software 7.7.5