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Topic: galvanic dissolved oxygen sensor (Read 285 times) previous topic - next topic

ARAS820

Hello

Hello

would you please help me for make dissolved oxygen sensor ?

i need circuit board.

i find any circuit board from this link :

https://wiki.dfrobot.com/Gravity__Analog_Dissolved_Oxygen_Sensor_SKU_SEN0237

in this circuit boar used TP5551 but i can not find this item .

1)i can not find TP5551  in my place then can i replacement by OP177GP  or   AD623AN   or   OP77GP   or    AD8572ARZ ? if i can do it then which of them is the best ?

2)If i can replacement TP5551 by another op-amp , is need change in circuit board or only i can replace without any change ?

3) if these op-amps  ( OP177GP  or   AD623AN   or   OP77GP   or    AD8572ARZ ) are not the best choices please tell me your offer.

would you please send answers by numbers questions .

thanks

jremington

The circuit is low impedance, so any rail-to-rail op amp specified for 3V (or less) single ended  operation should work.

The OP177G does not even come close, but the AD623 might work.

ARAS820

The circuit is low impedance, so any rail-to-rail op amp specified for 3V (or less) single ended  operation should work.

The OP177G does not even come close, but the AD623 might work.
do you have circuit board for dissolved oxygen sensor ?

If i  replacement TP5551 by AD623  ,  is need change in circuit board or only i can replace without any change ?

jremington

1. No

2. Do your homework: study the data sheets for the op amps.

MorganS

The link at the bottom of that blog post says that the kit costs $169 and it's in stock now: https://www.dfrobot.com/product-1628.html

What is stopping you from purchasing that kit?
"The problem is in the code you didn't post."

ARAS820

is circuit board of ph meter the same as circuit board dissolved oxygen sensor? can i use from circuit board of ph meter for circuit board of dissolved oxygen sensor ?

jremington

#6
Nov 12, 2019, 04:33 pm Last Edit: Nov 12, 2019, 04:35 pm by jremington
No. pH probes are completely different.

I suggest to buy the kit. It is clear that you have no idea what you are doing.

ARAS820

No. pH probes are completely different.

I suggest to buy the kit. It is clear that you have no idea what you are doing.
i am mechanical engineering  student also i must make mu own circuit board of dissolved oxygen sensor.

question 1-
why circuit board of pH probes are completely different compared with dissolved oxygen sensors? both of them send millivot and the circuit board must detect voltage. what are differents ?

Idahowalker

i am mechanical engineering  student also i must make mu own circuit board of dissolved oxygen sensor.

question 1-
why circuit board of pH probes are completely different compared with dissolved oxygen sensors? both of them send millivot and the circuit board must detect voltage. what are differents ?

The difference would be the thing being tested for.

pH is not dissolved oxygen.

jremington

#9
Nov 13, 2019, 12:37 am Last Edit: Nov 13, 2019, 12:38 am by jremington
Quote
what are differents ?
The probe impedance is vastly different. Look it up.

MorganS

i am mechanical engineering  student also i must make mu own circuit board of dissolved oxygen sensor.
You must make your own board but your professors haven't given you the training required. I suggest you take one or two years of electrical engineering classes and then try again.
"The problem is in the code you didn't post."

jremington

Quote
i am mechanical engineering  student also i must make mu own circuit board of dissolved oxygen sensor.
Either you misunderstood the assignment, or your professors are unreasonable idiots. Take your pick.

ARAS820

how has program of dissolved oxygen sensor for calibration and compensate of temperature and salinity and pressure ?

wvmarle

DF Robot has code on their page that's doing temperature compensation. You'll have to do your own research on the other two.

They also have the complete circuit of their board posted; that should make it easy to reproduce. OpAmp should be a low noise one that's suited for high gain applications, the circuit uses a gain of almost 37x.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

ARAS820


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