Correct Bill!
Also, concerning the so-called comparison by Coilcraft, I didn't want to sound
biased so I did some research to prove my point. It is as follows;
The comparison was done using the below different pieces of test equipment.
HP 4191A
4-1/2 digist
1 MHz to 1 GHz
Requires special test fixtures per HP spec sheet
3 ppm accuracy
"'evaluation' of LCR components".
Same functions as the HP 4192A except higher test frequency.
==========
HP 4192A
Impedance analyzer
Requires user to calculate L from impedance and frequency.
5 Hz to 13 MHz frequency range
Performs both network analysis and impedance analysis
+/- 50 ppm frequency accuracy
==========
HP 4342A;
Analog Q meter
22 kHz to 70 MHz frequency range in seven bands
unless it has option 001;
Frequency Range (10kHz to 32MHz)
Measures Q from 5 too 1000
Measures L from 0.09 uH to 1.2 H at 7 frequencies according to HP spec sheet.
Measures dissipation factor and dielectric constant of insulating materials
Measures the coefficient of coupling, mutual inductance, and frequency response
of transformers.
Push button operation of frequency range and Q/Delta Q range selection
1% resolution
Accuracy +/- 3% after substitution of residuals (10 nH)
==========
Boonton 62AD Inductance Meter (3-1/2 digit)
Two wire measurements
1 MHz oscillator.
0.001 to 2000 uH measurement by manual.
Scale is 2 to 2000 uH.
0.5% accuracy
Model 62AD measures equivelant series inductance. Q's given are the result of
series resistance. If loss appears in parallel with the test speciman, the 62AD
will read the equivelant series inductance, IE; a 10 uH with a Q of 1, owing to
parallel loss will measure 5 uH which is the equivelant series inductance.
==========
Tektronix LC-130 (1959-1966 catalogs)
125 to 40kHz
Inductance ranges are: 0 to 3, 10, 30, 100, 300 µH
Capacitance ranges are: 0 to 3, 10, 30, 100, 300 pF
Minimum scale division is 0.1 uH or pF
Must use correction curve in manual for shunt inductance and series
capacitance. Warm up time can be an accuracy factor. At least 15 minutes warm
up is specified. Also see correction charts in manual for parallel and series
differences.
Accuracy +/- 3% of full scale. According to the Tek manual, when calibrated
with the S-30 delta standard, accuracy of 1% of full scale can be obtained.
Analog vacuum tube LC meter
Two wire measurement with a guard (if used?)
==========
Meguro MQ-171 (Chinese analog type with digital counter)
20-230 MHz in 4 bands
Q = 10 to 750 in 3 ranges
Delta Q 0 to 50 in two ranges (X10 mag)
Accuracy = +/- 15% < 100 MHz
Resonating C range 7 to 100 pF
http://www.hitek.co.kr/products/ate/meguro_q.htm
First, this comparison didn't compare apples to apples, and you can see from
the ranges these meters should check an inductor at what's going on here. Read
their PDF file Coilcraft document 119-1 that the link was listed the other day
to.
A 1.065 uH was the DUT as measured by the HP 4191A in the comparison for all
meters.
They mention a Q meter needs standards to measure inductors correctly, so why
did they get an erroneous reading? They say it's very accurate when using
standards.
Quote;
"Correlation pieces are deemed to be the standard for a particular component
part and are used to setup each instrument every time a test is performed.
Correlation is still the traditional method and results in very little error,
excellent repeatability and is applicable at any frequency. However, the method
of correlation has significant logistical disadvantages: the establishment and
accountability of specific correlation pieces between the manufacturer and the
customer, as well as the task of adjusting every instrument for each test".
The example uses a totally different DUT, saying it is 53.8 nH and only
compares the HP 4191A to the Meguro MQ-171 which has an accuracy of 15% at 100
MHz or under. That means it's accuracy is worse as the frequency is higher.
Where did the other meters go to? Where are the example tests to compare them?
Don't forget to check out the tolerances and ranges of each piece of equipment,
and you tell me what's up?
Sincerely,
Will
*********** REPLY SEPARATOR ***********
On 8/8/06 at 9:49 AM Bill Turner wrote:
>ORIGINAL MESSAGE:
>
>On Mon, 7 Aug 2006 06:49:51 -0700, you wrote:
>
>
>>use of the dip meter and magic
>>wire
>
>------------ REPLY SEPARATOR ------------
>
>Please guys, this is how flame wars start.
>
>There is nothing at all "magic" about nichrome wire. It's
>characteristics and usage have been explained in great detail and you
>can believe them or not as you wish.
>
>If you have some data which either proves or debunks the usefulness of
>nichrome, let's hear it, but please no implied insults.
>
>Thanks,
>
>Bill, W6WRT
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