I am looking for the characterisation of a 037 MPS (0 280 100 037). Does anyone know what typical inductance values (H) should be for a series of vacuum levels (in. Hg)?
I have a leaking 037 MPS, a rebuilt 043 MPS and I am expecting a 049 MPS. My car is a '73 914-4 2.0L FI. I believe the 037 MPS is my car’s original one. I was going to try to adjust the 043 MPS and the 049 MPS to the same specs as my leaking 037 MPS which has not been rebuilt and still has the epoxy seal on it. So I took measurements of the 037 MPS with a vacuum pump and a multimeter to measure the inductance. I was surprised to get inductance values quite different from the ones Paul B. Anders is displaying on his site for a 037 MPS. You can see a video clip and a chart showing the vacuum and inductance measurements of my MPS here.
According to Paul B. Anders, the 037 MPS inductance values for 0 in. Hg, 4 in. Hg and 15 in. Hg should be 1.44 H, 1.26 H and 0.72 H respectively. This is at his altitude of 1,280’. These values corrected for the pressure at sea level are 1.49 H, 1.22 H and 0.77 H. This is quite different from the values I measured on my MPS, which are respectively 1.13 H, 0.92 H and 0.67 H.
Does anyone else have typical inductance data for a 037 MPS?
Cheers!
JF
Full Version: 037 MPS characterisation
QUOTE(velum @ Oct 10 2009, 09:59 AM) 
I am looking for the characterisation of a 037 MPS (0 280 100 037). Does anyone know what typical inductance values (H) should be for a series of vacuum levels (in. Hg)?
I have a leaking 037 MPS, a rebuilt 043 MPS and I am expecting a 049 MPS. My car is a '73 914-4 2.0L FI. I believe the 037 MPS is my car’s original one. I was going to try to adjust the 043 MPS and the 049 MPS to the same specs as my leaking 037 MPS which has not been rebuilt and still has the epoxy seal on it. So I took measurements of the 037 MPS with a vacuum pump and a multimeter to measure the inductance. I was surprised to get inductance values quite different from the ones Paul B. Anders is displaying on his site for a 037 MPS. You can see a video clip and a chart showing the vacuum and inductance measurements of my MPS here.
According to Paul B. Anders, the 037 MPS inductance values for 0 in. Hg, 4 in. Hg and 15 in. Hg should be 1.44 H, 1.26 H and 0.72 H respectively. This is at his altitude of 1,280’. These values corrected for the pressure at sea level are 1.49 H, 1.22 H and 0.77 H. This is quite different from the values I measured on my MPS, which are respectively 1.13 H, 0.92 H and 0.67 H.
Does anyone else have typical inductance data for a 037 MPS?
Cheers!
JF
On his site, Paul Banders mentions that a DMM-based inductance meter may return an inaccurate measurement. Maybe this is why your numbers differ?
QUOTE(davesprinkle @ Oct 10 2009, 01:20 PM)
QUOTE(velum @ Oct 10 2009, 09:59 AM)
I am looking for the characterisation of a 037 MPS (0 280 100 037). Does anyone know what typical inductance values (H) should be for a series of vacuum levels (in. Hg)?
I have a leaking 037 MPS, a rebuilt 043 MPS and I am expecting a 049 MPS. My car is a '73 914-4 2.0L FI. I believe the 037 MPS is my car’s original one. I was going to try to adjust the 043 MPS and the 049 MPS to the same specs as my leaking 037 MPS which has not been rebuilt and still has the epoxy seal on it. So I took measurements of the 037 MPS with a vacuum pump and a multimeter to measure the inductance. I was surprised to get inductance values quite different from the ones Paul B. Anders is displaying on his site for a 037 MPS. You can see a video clip and a chart showing the vacuum and inductance measurements of my MPS here.
According to Paul B. Anders, the 037 MPS inductance values for 0 in. Hg, 4 in. Hg and 15 in. Hg should be 1.44 H, 1.26 H and 0.72 H respectively. This is at his altitude of 1,280’. These values corrected for the pressure at sea level are 1.49 H, 1.22 H and 0.77 H. This is quite different from the values I measured on my MPS, which are respectively 1.13 H, 0.92 H and 0.67 H.
Does anyone else have typical inductance data for a 037 MPS?
Cheers!
JF
On his site, Paul Banders mentions that a DMM-based inductance meter may return an inaccurate measurement. Maybe this is why your numbers differ?
I just tested my (working) 043 MPS and obtained numbers more like yours: 1.03H, 0.92H and 0.62H. (Paul has 1.39, 1.18 and 0.71 for the 043.) My elevation is about 864ft, so around 730 Torr and the correction to Paul's numbers would be 730/723 - hardly any difference.
I used a very good TES multimeter that is capable of measuring up to 40H. Another check would be to put a capacitor in parallel, and frequency sweep the circuit for a maximum, and calculate the implied inductance. Perhaps I'll do that
(With a 150nF capacitor, I think the resonant frequency would be around 400Hz - and would change with vacuum - this might make a novel electronic musical instrument to suck and blow!)This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.