Comparison: WPS500 and FirstLook versus Nicholson's
UPDATE: Bounty raised to 5DNT, and an additional TA197 attenuator request has been added. Please see below.
This request is for people lucky enough to have the WPS500 and both FirstLook and Nicholson's sensors. I'm interested in checking some math behind those three, so please try the following with the Pico4425:
- Make a three-way splitter to connect all three sensors to the Intake Manifold.
- Put WPS500 into range 3 (but no Zoom Mode) -- to collect actual pressure on Ch A.
- FLS connected according to the instructions, on Ch B.
- Nicholson's sensor connected according to the instructions, on Ch C.
- Starter current on Ch D.
AND perform three experiments with fuel delivery disabled:
- Cranking at WOT;
- Cranking with a closed or blocked off throttle (expecting 3psi vacuum or more).
- Same as 2, but with Nicholson's sensor connected through TA197 attenuator (10:1, 8MOhm input impedance).
PsData captures are to be performed at 1 or 2 sec/div timebase, Number of samples box: 1MS. Both Key Start and Key Off events should be present on the waveform. It is very important to avoid voltage overrange on Ch A-C.
Any car will do, but the more cylinders the better. Please include the engine details.
Hello Dmitriy, What is the part number of: First look sensor ? Nicholson's sensors ? Thank you
Hi Jaxon, First look is available from various vendors or Picoscope directly: picoauto.com/products/press… Nicholson’s version of the pulse sensor is mentioned here: diag.net/msg/m3zwuqb1ne… and here: diag.net/msg/m1nr42cbda…
Wish I could help I have the wps500 and first look but this is the first im hearing of nicholson treid to find it on the internet but came up empty
Look him up on face book michael nicholson
Well, I’ve heard there is a website called diag.net that also has a search button :) diag.net/msg/mavlgqarip…
If this is still open next week I can borrow an FLS, I have the other 2 items on the list. Does the captures need to be done with a 4425? I have a 4423 that's the reason I ask.
Cliff, the 4423 would work just as well. Let’s see if someone has all three and makes the capture soon or not. Thank you!
Dmitriy, This isn't exactly what your looking for but I thought I would contribute what I could. I did not have my WPS, but I was at the CTI Research center and had some time available to play with my Nicholson Sensor and a First Look Sensor. I performed closed throttle RC tests with both connected. The vehicle is a 2019 Toyota Rav4 2.5 4cyl. I am teed into the intake at the same spot and…
Thank you for the captures, Richard! I have taken a look at the signals, and that made me even more interested in seeing the WPS trace as well! The goal of the experiment is not just comparing FLS and Nicholson, but establishing a mathematical link between all three... as the WPS dips into some vacuum and back to atmospheric again. For the voltage ranges -- I think it is better to use the ones…
Richard and everyone interested in the topic, I have given a thought to the voltage scales for the two sensors being different. Piezoelectric sensors are high impedance voltage generators and even oscilloscope's 1MOhm input impedance can change their frequency response. If I understand correctly, in the Nicholson's version the piezoelectric sensor is connected to the leads directly. Thus, it…
So I was looking at your Pico files Richard. I found it interesting that the nicholson sensor seems to have a perfect rock solid amplitude, while the FLS seems to increase in amplitude. Any reason for that??
This is the first time that I've looked at these captures. I agree Caleb. Why is the amplitude changing in the Firstlook but not in the Nicholson Sensor?
Hey Dmitriy. I would love to participate I just don't have a First Look. I have a Nicholson and a WPS 500. Kinda hard to spend the money on a First Look when a Nicholson is a fraction of the cost and performs flawlessly. Anyway just my 2 cents but definitely a cool post nonetheless!
Thanks, Caleb! I hope that one of these days Richard is going to find time for this experiment and we will have the whole picture.
My NPS finally came in that I'm making my coworker buy :D I already had two FLS, so I got you a bonus capture comparing two NPS and two FLS in the same capture. Let me know if you need anything else. Car is a 2006 Audi A4 2.0T CCTA, 138809 miles. I just realized I didn't change the lead to 10:1 when I used the attenuator. I have to finish the oil change on that particular car and then it has…