Calibration for analog sensor (voltage, resistance and NTC sensors)

Tips for UTCOMP's features and tutorials for assembling additional sensors in vehicles.
Daily_Driver
Posts: 21
Joined: Sat Dec 03, 2016 4:41 pm
Has thanked: 5 times
Been thanked: 1 time

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby Daily_Driver » Tue Dec 06, 2016 1:52 pm

Thanks for the info.

At a minimum, I want to read the following factory sensors:
MAP (for boost, 0-5V, have factory data table)
Coolant temperature (0-5V, have factory data table)
Oil pressure (resistance in ohms to be determined)

As I read the manual, I do not need to read fuel level in order to display fuel economy and distance to empty. My car has an 8K pulse per mile speed sensor and I can connect to fuel injector #1 for the (-) PWM signal needed.

I'm also using an added oil temperature sensor, it is a General Motors part and it has a data table (click for PDF). I will likely add a 0-5V fuel pressure sensor as well.

The factory MAP sensor has the data for pressure:volts from 14.31 PSI down to 24.01 hg.

For the coolant sensor, the car uses two- one for the gauge (resistance) and another for the ECU (voltage). I found the following data for the ECU sensor has data for temperature:volts from 110 degrees (F) up to 220 degrees.

For the oil pressure sender, I can use an air compressor and an ohm meter to get data points, but it should be about
10 PSI: 45-55 Ohms or Open,
90 PSI: 35-40 Ohms.

I'll use Adc 1 for MAP, Adc 2 for coolant, Adc 3 for oil pressure, Adc 4 for oil temperature, and AdcVcc1 for fuel pressure. I can use the 18B20 for ambient outside air temperature and another inside if needed.

Let me know if any of this appears to be erroneous. I appreciate your help with my planning here.
Installing the UT Comp Pro on my car

ArT
Posts: 1103
Joined: Wed Mar 25, 2015 8:54 am
Location: Warsaw, Poland
Has thanked: 27 times
Been thanked: 101 times

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby ArT » Wed Dec 07, 2016 10:47 am

Daily_Driver wrote:At a minimum, I want to read the following factory sensors:
MAP (for boost, 0-5V, have factory data table)
Coolant temperature (0-5V, have factory data table)
Oil pressure (resistance in ohms to be determined)

As I read the manual, I do not need to read fuel level in order to display fuel economy and distance to empty. My car has an 8K pulse per mile speed sensor and I can connect to fuel injector #1 for the (-) PWM signal needed.


Yes, you can use fuel consumption to get also fuel level and estimated distance to refuel. You will need to reset stats each time you refuel - if you do not do that than 2 functions will not work: fuel level and distance to refuel.

Daily_Driver wrote:I'm also using an added oil temperature sensor, it is a General Motors part and it has a data table (click for PDF).
(...)
For the coolant sensor, the car uses two- one for the gauge (resistance) and another for the ECU (voltage). I found the following data for the ECU sensor has data for temperature:volts from 110 degrees (F) up to 220 degrees.

You can connect this sensor but you will need to calibrate (scale) it. If you have already this sensor working with ECU in car than you should connect it to AdcX input. If you do not have connected this sensor yet you should connect it to AdcVccX.
If you do not want to scale it, than you can use also any digital DS18B20 sensor from kit - tutorial: viewtopic.php?f=28&t=120 or use already calibrated sensor: http://www.reveltronics.com/en/shop/59/ ... ter-detail


Daily_Driver wrote:The factory MAP sensor has the data for pressure:volts from 14.31 PSI down to 24.01 hg.

MAP is linear sensor, just connect it to any AdcX input and scale in software (you will need convert PSI/hg to BAR for scaling).


Daily_Driver wrote:(...) I will likely add a 0-5V fuel pressure sensor as well.(...)_
For the oil pressure sender, I can use an air compressor and an ohm meter to get data points, but it should be about
10 PSI: 45-55 Ohms or Open,
90 PSI: 35-40 Ohms.

It is very low range sensor - are you sure that these data are correct? Usualy Oil pressure sender (resistance) is in range 240-33 Ohm for 0-10 bar (0-150 PSI). Anyway - if you have this sensor already powered in car, than you should read voltages (not resistance). Just connect it to AdcX input and scale (you can view voltages in UTCOMP software - in "readings" tab. If you do not have it connected in car yet - than you should connect it to AdcVccX. You should get minimum 1V range to get accurate readings. If you will have low range readings (e.g. 0.1 - 0.3V) than I recommend to assembly other sensor, e.g. http://www.reveltronics.com/en/shop/60/ ... -5v-detail (this type of sensor gives already voltage on output).



Daily_Driver wrote:I'll use Adc 1 for MAP, Adc 2 for coolant, Adc 3 for oil pressure, Adc 4 for oil temperature, and AdcVcc1 for fuel pressure. I can use the 18B20 for ambient outside air temperature and another inside if needed.

Adc 1 for MAP - ok
Adc 2 for coolant - ok if you have already connected it in car (AdcVccX otherwise)
Adc 3 for oil pressure - ok if you have already connected it in car (AdcVccX otherwise for resistance sensor)
Adc 4 for oil temperature - ok if you have already connected it in car (AdcVccX otherwise)
AdcVcc1 for fuel pressure - ok if you assembly additional resistance type sensor (AdcX otherwise)
DS18B20 for air temps - ok.

You will have also 2 more DS18B20 sensors left, it has up to 125C range so it will be also fine for coolant and for oil (in many cases). Please take a look for this tutorial: viewtopic.php?f=28&t=127

Daily_Driver
Posts: 21
Joined: Sat Dec 03, 2016 4:41 pm
Has thanked: 5 times
Been thanked: 1 time

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby Daily_Driver » Fri Dec 09, 2016 7:00 am

Next question:
I have downloaded the 3.4 software, and am setting it up to match what I want to do.
For my fuel pressure sensor, it also is not connected to the ECU. It will be a 3-wire transducer that operates on 5V. It will output .5 to 4.5V for 0-150 PSI. I've read the tutorial and can use pin A18 to supply 5V. I take it I'll ground it to where pin A12 is grounded, and run the signal wire to Adc3 (B2).

When I look at the AdcX options, I see "Fuel pressure sensor (diesel common-rail). There is no fuel pressure only setting. Since my car is not a diesel, will this operate/display correctly for fuel pressure, to include data logging?
Installing the UT Comp Pro on my car

ArT
Posts: 1103
Joined: Wed Mar 25, 2015 8:54 am
Location: Warsaw, Poland
Has thanked: 27 times
Been thanked: 101 times

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby ArT » Fri Dec 09, 2016 12:54 pm

Yes, but fuel pressure measurement will affect on fuel consumption measurements (if you choose fuel pressure on Adc input than UTCOMP will include this measurement in fuel consumption). Petrol engines has fuel pressure regulator and fuel pressure on injectors (in comparison to pressure in manifold) is constant. If you will measure fuel pressure in comparison to atmospferic pressure than you will have error in fuel consumption measurements.

In conclusion - you can get fuel pressure readings but if you want to have fuel consumption measurement than we will need to prepare custom version to not include this measurement in fuel consumption.

Daily_Driver
Posts: 21
Joined: Sat Dec 03, 2016 4:41 pm
Has thanked: 5 times
Been thanked: 1 time

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby Daily_Driver » Fri Dec 09, 2016 3:54 pm

Yes, but fuel pressure measurement will affect on fuel consumption measurements (if you choose fuel pressure on Adc input than UTCOMP will include this measurement in fuel consumption). Petrol engines has fuel pressure regulator and fuel pressure on injectors (in comparison to pressure in manifold) is constant. If you will measure fuel pressure in comparison to atmospheric pressure than you will have error in fuel consumption measurements.

To add more info, my turbocharged car has a rising rate fuel pressure regulator (RRR) due to it having larger injectors. The original regulator added 1 PSI of fuel pressure for each PSI of boost. I'm not sure what the exact amount is for the RRR, but I think it is close to 2 PSI for each PSI of boost.

I have two ECU choices, one is a custom calibration for the 1:1 regulator and larger injectors, the other is a stock ECU for use with the RRR. With the stock ECU, base fuel pressure is dropped to about 22 PSI (from stock 55 PSI), and the RRR adds more fuel under boost. If it is better for UT Comp Pro use, I can use the modified ECU, stock fuel pressure, and a 1:1 ratio.

I thought fuel consumption used the (-) injector signal? I don't have an input choice for pin A10 other than the drop down box at the top (PWM (-) [controlled by GND]), so I'm presuming that is the (-) injector wire.

Using the calculator on the advanced tab, I obtained a= 2.59 and b= -1.29 for the 0-150 PSI sensor where 0V= .5 PSI (or 0 bar) and 4.5V= 150 PSI (or 10.34 bar).

Before installation, I flow tested my larger injectors at several different pressures, for example the average flow @ 55 PSI was 692.67 mL/minute, which is .0115 liters/second.
Installing the UT Comp Pro on my car

ArT
Posts: 1103
Joined: Wed Mar 25, 2015 8:54 am
Location: Warsaw, Poland
Has thanked: 27 times
Been thanked: 101 times

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby ArT » Sun Dec 11, 2016 5:26 pm

Yes you should connect ground control injector signal.
If you will have vary pressure, than you should also connect fuel pressure sensor.

Daily_Driver
Posts: 21
Joined: Sat Dec 03, 2016 4:41 pm
Has thanked: 5 times
Been thanked: 1 time

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby Daily_Driver » Mon Dec 12, 2016 4:15 pm

I have been using the NTC calculator spreadsheet. I found the temperature sender sold here with the suggested A, t, and T0 values (-1.0, -1.1, 141.3) had a wide variance range- such as
Temp actual, variance reported (closer to 0 is better)
60: -26
70: -22
80: -20
90: -17
100: -14
110: -10
120: -3
130: 6
140: 18
150: 31

I changed these to -20, -2.4, 200 and got better results for the main usable range (70-100 C, 158-212 F), even the extreme low and high were much closer:
50: -12
60: -5
70: -1
80: 1
90: 1
100: 0
110: -2
120: -3
130: -2
140: 1
150: 5

Is there any reason why these would not work? Is there a limit to the A, t, and T0 values?
Installing the UT Comp Pro on my car

ArT
Posts: 1103
Joined: Wed Mar 25, 2015 8:54 am
Location: Warsaw, Poland
Has thanked: 27 times
Been thanked: 101 times

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby ArT » Mon Dec 12, 2016 4:43 pm

Calibration data for this sensor is for VREF=5.2V. I think that your calibration data is for VREF=5.0V . Now all UTCOMP modules has VREF = 5,2V* (UTCOMP-PRO are hand calibrated to get best accuracy - real VREF can be displayed in "readings" tab in application).

*why 5,2V not 5,0V? Because some 5V sensors can give slightly higher voltage at output (e.g. 5.05V). VREF=5.2V gives 0 - 5.2 measurement range.

Daily_Driver
Posts: 21
Joined: Sat Dec 03, 2016 4:41 pm
Has thanked: 5 times
Been thanked: 1 time

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby Daily_Driver » Mon Dec 12, 2016 5:16 pm

Thank you, I missed that sender was calibrated at 5.2V. I am still working on finding a good curve for my GM coolant temperature sensor. I won't be able to fine tune it until I buy the UT Comp Pro.
Installing the UT Comp Pro on my car

Kaldek
Posts: 36
Joined: Sun May 29, 2016 3:32 am
Has thanked: 4 times
Been thanked: 2 times

Re: Calibration for analog sensor (voltage, resistance and NTC sensors)

Postby Kaldek » Sat Dec 17, 2016 11:14 pm

ArT wrote:Yes, but fuel pressure measurement will affect on fuel consumption measurements (if you choose fuel pressure on Adc input than UTCOMP will include this measurement in fuel consumption).


Why does the UTCOMP factor in the fuel pressure reading? The fuel pressure regulator ensures that the relative pressure in the fuel rail is always the same, so that the fuel delivered per injector pulse is always constant.

I just don't see why the UTCOMP would factor in the rail pressure. It makes no sense - no ECU factors in rail pressure for fuel consumption calculation, so why does UTCOMP?


Return to “Tutorials”

Who is online

Users browsing this forum: No registered users and 1 guest

cron