Isotest 6 - Additional applications (translation)
ID: 132442
Isotest 6 - Additional applications (translation)
30.Jan.07 17:13
0
Greetings Herr Heigl and Herr Bauer. . . .
and also to Ake Nyholm
As noted by the email to Herr Bauer, and in total agreement with the outstanding article posted by Herr Heigl which supplements the development and production of his Isotest series of instruments, and specifically the ISOTEST 6 model, I have begun my slow translation.
I hope this rough translation from Babelfish will serve as a beginning . . . .I am certain there will shortly be a final "more accurate and proper" version from one of our many proficient bilingual members.
Many thanks to Gerhard Heigl for the excellent description and illustrations to a very useful test equipment item.
I normally continue to replace the ? with the ohms, resistance, or whichever terminology is appropriate. And many other words which the typical software translators do not "understand".
If any other member knows of a better "free translator" which will accept larger files than Babelfish, and improve upon the capability to translate the technical terms of our hobby, all members would most likely benefit. There is another free translator, FreeTranslations - however, it refuses to accept any file larger than 750 characters. . . . .a very (very) small file.
Translation follows - the graphics obviously do not "compose" (render) in these operations.
Respectfully,
Robert Sarbell
Please note that the translation that follows has been "revised significantly" and with the utmost assistance of our esteemed senior member Her Konrad Birkner. . . . .
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I must admit that I developed the ISOTEST mainly for insulation (leakage) checks of capacitors.But it can do much more beyond that. Here are a few examples
For tests at mains operated equipment always disconnect the power cord from the line. Pull the plug. Switching off is not sufficient !
Note: Added by this collector (An ON-OFF switch may rarely fail in the "ON" position - and could cause serious personal injury or major damage to equipment)
1)
Coupling capacitors need an insulation resistance far beyond 200M ohms. That is out of the ISOTEST range. But there is a knack to find out if a sample is appropriate as a coupling capacitor. The sample (Cp) is charged with the rated voltage(A). If the Isotest indicates (infinite resistance) ∞ , disconnect Cp carefully while the test voltage remains on (B). Wait at least 10 seconds, and then reconnect Cp to the Isotest, which is still on.The instrument pointer must not show a deflection or movement. If it does, then Cp is not suitable as a coupling capacitor. Do not vary the test voltage. For small capacitance values (< 0.01µF) a supplementary capacitor (Ch = approx.0.1µF) is connected in parallel. The supplementary capacitor, Ch, should display an extremely high insulation value (∞) and sufficient voltage rating.
NOTE: the longer you wait, the test becomes more doubtful.
2)
A rather coarse check of rectifiers is also possible, regardless of their material: germanium, silicon, copper oxide, or selenium.
Silicon diodes and bridge rectifiers should indicate ∞ in reverse polarity.
Good selenium rectifiers usually show 2 to 50M ohms in reverse, depending on their voltage rating. Forward resistance should be as low as possible for all rectifier types. Disconnect diodes and rectifiers completely from their circuitry. Do not exceed the rated voltage!
3)
Transformers of any kind and size may be tested for insulation faults of winding to core, or from winding to winding. An indication of ∞ would be ideal. The measured real values have to comply with existing regulations and specifications. This in particular for mains operated equipment and installations.
If a leak current limiting switch (so called FI-switch ) in an installation is triggered: Home appliances like refrigerator, electric kitchen range, microwave oven, dish washer, washing machine, tumbler etc. may be checked for hidden leakage/insulation faults. Disconnect the unit completely from mains and apply the maximum test voltage (500 V).
4)
To check 3-phase motors and induction (squirrel cage) type motors every jumper /bridge in the terminal box must be removed. This measure will be helpful if a fault needs to be localized. Ideally the Isotest should indicate ∞. Measured values must comply with national/international regulations, in particular for mains operated equipment and installations.
Testing cables or lines of greater length will result in a small pointer deflection, caused by the mutual capacitance between conductors (wires), respectively against ground.
Standard ohmmeters or digital multimeters are not suitable due to their low test voltage.
5)
For glow discharge devices (e.g. neon lamps) the approximate values of ignition voltage and arc drop can be determined (conduction voltage). Slowly increase the test voltage until ignition occurs, which will causes an indication on the instrument. The light will be very dim due to the 10 Megohm source resistance of the Isotest. If the test voltage is now slowly reduced, the indication will jump back below the arc drop (conducting) voltage: then the glow will go out.
The 2nd view shows a simple audio oscillator. It makes use of the hysteresis between ignition and conducting voltage. The frequency of the sawtooth pulse can be varied by C1 and by the test voltage setting. C2 acts as a blocking capacitor for the test voltage to keep it away from the output.
6)
You may also test tubes for internal leakage. Check all pins /contacts mutually against each other. Except filament to filament and internal connections (see applicable base diagram) there must not be any indication below ∞.
Sockets sometimes develop leakage paths, from contamination and flashover. For these tests all leads have to be unsoldered. Do not forget to check against chassis, too.
Even identification of unknown tube connections is possible using the Isotest.
Here the filament needs to be heated. See EF27.
--------------------------------------------------------------------------------------------------------------------------------------
Respectfully,
Robert Sarbell
PS: For the English-speaking members who were not fortunate enough to purchase one of the ISOTEST 6 kits when introduced by Herr Heigl (some time ago), I wish to add that the unit has been of significant benefit to this member and one of our esteemed collectors in South America.
and also to Ake Nyholm
As noted by the email to Herr Bauer, and in total agreement with the outstanding article posted by Herr Heigl which supplements the development and production of his Isotest series of instruments, and specifically the ISOTEST 6 model, I have begun my slow translation.
I hope this rough translation from Babelfish will serve as a beginning . . . .I am certain there will shortly be a final "more accurate and proper" version from one of our many proficient bilingual members.
Many thanks to Gerhard Heigl for the excellent description and illustrations to a very useful test equipment item.
I normally continue to replace the ? with the ohms, resistance, or whichever terminology is appropriate. And many other words which the typical software translators do not "understand".
If any other member knows of a better "free translator" which will accept larger files than Babelfish, and improve upon the capability to translate the technical terms of our hobby, all members would most likely benefit. There is another free translator, FreeTranslations - however, it refuses to accept any file larger than 750 characters. . . . .a very (very) small file.
Translation follows - the graphics obviously do not "compose" (render) in these operations.
Respectfully,
Robert Sarbell
Please note that the translation that follows has been "revised significantly" and with the utmost assistance of our esteemed senior member Her Konrad Birkner. . . . .
------------------------------------------------------------------------------------------------------------
I must admit that I developed the ISOTEST mainly for insulation (leakage) checks of capacitors.But it can do much more beyond that. Here are a few examples
For tests at mains operated equipment always disconnect the power cord from the line. Pull the plug. Switching off is not sufficient !
Note: Added by this collector (An ON-OFF switch may rarely fail in the "ON" position - and could cause serious personal injury or major damage to equipment)
1)
Coupling capacitors need an insulation resistance far beyond 200M ohms. That is out of the ISOTEST range. But there is a knack to find out if a sample is appropriate as a coupling capacitor. The sample (Cp) is charged with the rated voltage(A). If the Isotest indicates (infinite resistance) ∞ , disconnect Cp carefully while the test voltage remains on (B). Wait at least 10 seconds, and then reconnect Cp to the Isotest, which is still on.The instrument pointer must not show a deflection or movement. If it does, then Cp is not suitable as a coupling capacitor. Do not vary the test voltage. For small capacitance values (< 0.01µF) a supplementary capacitor (Ch = approx.0.1µF) is connected in parallel. The supplementary capacitor, Ch, should display an extremely high insulation value (∞) and sufficient voltage rating.
NOTE: the longer you wait, the test becomes more doubtful.
2)
A rather coarse check of rectifiers is also possible, regardless of their material: germanium, silicon, copper oxide, or selenium.
Silicon diodes and bridge rectifiers should indicate ∞ in reverse polarity.
Good selenium rectifiers usually show 2 to 50M ohms in reverse, depending on their voltage rating. Forward resistance should be as low as possible for all rectifier types. Disconnect diodes and rectifiers completely from their circuitry. Do not exceed the rated voltage!
3)
Transformers of any kind and size may be tested for insulation faults of winding to core, or from winding to winding. An indication of ∞ would be ideal. The measured real values have to comply with existing regulations and specifications. This in particular for mains operated equipment and installations.
If a leak current limiting switch (so called FI-switch ) in an installation is triggered: Home appliances like refrigerator, electric kitchen range, microwave oven, dish washer, washing machine, tumbler etc. may be checked for hidden leakage/insulation faults. Disconnect the unit completely from mains and apply the maximum test voltage (500 V).
4)
To check 3-phase motors and induction (squirrel cage) type motors every jumper /bridge in the terminal box must be removed. This measure will be helpful if a fault needs to be localized. Ideally the Isotest should indicate ∞. Measured values must comply with national/international regulations, in particular for mains operated equipment and installations.
Testing cables or lines of greater length will result in a small pointer deflection, caused by the mutual capacitance between conductors (wires), respectively against ground.
Standard ohmmeters or digital multimeters are not suitable due to their low test voltage.
5)
For glow discharge devices (e.g. neon lamps) the approximate values of ignition voltage and arc drop can be determined (conduction voltage). Slowly increase the test voltage until ignition occurs, which will causes an indication on the instrument. The light will be very dim due to the 10 Megohm source resistance of the Isotest. If the test voltage is now slowly reduced, the indication will jump back below the arc drop (conducting) voltage: then the glow will go out.
The 2nd view shows a simple audio oscillator. It makes use of the hysteresis between ignition and conducting voltage. The frequency of the sawtooth pulse can be varied by C1 and by the test voltage setting. C2 acts as a blocking capacitor for the test voltage to keep it away from the output.
6)
You may also test tubes for internal leakage. Check all pins /contacts mutually against each other. Except filament to filament and internal connections (see applicable base diagram) there must not be any indication below ∞.
Sockets sometimes develop leakage paths, from contamination and flashover. For these tests all leads have to be unsoldered. Do not forget to check against chassis, too.
Even identification of unknown tube connections is possible using the Isotest.
Here the filament needs to be heated. See EF27.
--------------------------------------------------------------------------------------------------------------------------------------
Respectfully,
Robert Sarbell
PS: For the English-speaking members who were not fortunate enough to purchase one of the ISOTEST 6 kits when introduced by Herr Heigl (some time ago), I wish to add that the unit has been of significant benefit to this member and one of our esteemed collectors in South America.
To thank the Author because you find the post helpful or well done.
30.Jan.07 18:51
Greetings across the pond!
I will try my best. It should be not too difficult to beat Babelfish (even with my limited English).
Best regards,
KoBi
To thank the Author because you find the post helpful or well done.
31.Jan.07 00:35
Greetings Kobi,
I am certain that your translation will be impeccable - there are no limits for you! I am still slowly going through the text, and also trying to negotiate with a seller (non-RMO member) for a lovely 1930 original Stewart Warner reproducer for my restored, and slightly "scarred" cabinet. I took your sage advice and left it as it was.
It plays quite nice, but I hope to install an original model 565A speaker.
Meanwhile, I will continue my "OJT" (on-the-job training) and see if I understand correctly the procedures you translate from Gerhard's kind offering.
Respectfully,
Robert
PS: I have recently acquired a very nice (functional) chassis for a 1931 Stewart Warner model R100A with the tone control - the cabinet has been missing for a long time.
I am certain that your translation will be impeccable - there are no limits for you! I am still slowly going through the text, and also trying to negotiate with a seller (non-RMO member) for a lovely 1930 original Stewart Warner reproducer for my restored, and slightly "scarred" cabinet. I took your sage advice and left it as it was.
It plays quite nice, but I hope to install an original model 565A speaker.
Meanwhile, I will continue my "OJT" (on-the-job training) and see if I understand correctly the procedures you translate from Gerhard's kind offering.
Respectfully,
Robert
PS: I have recently acquired a very nice (functional) chassis for a 1931 Stewart Warner model R100A with the tone control - the cabinet has been missing for a long time.
To thank the Author because you find the post helpful or well done.