Is the unit for the oxygen content displayed as "ppm" a volume ratio, a mass ratio or a molar ratio? All three are measured in ppm, but have different values (ppmV, ppmM or ppmn). |
Regarding the 3190 and its RS-232 interface:.
1) Is a hard or software handshake used ? (RTS / DTR or XON / XOFF)
2) Is a standard or modified cable necessary ? (Standard cable with Pin 2-3 / 3-2 / 4-6/ 6-4/ 7-8 / 8-7/ 5-5)
3) Is any jumper setting inside of the 3190 ?
4) Which kind of data will be transmitted ? (ASCII signs, values INT,..)
What does the transmission look like ? (Header, Data,- Data length, type, speed)
How can I detect a complete transmission ? (end sign, fixed transmission length, time length)
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Why is the sensor failure alarm triggered when the Span value (ppm) / Cell output(nA) is over 4.447 ppm/nA? |
On a 3190, what would cause the display to read "0000" and/or "5000" during calibration? |
How do you retrofit a 3190 from AC to DC power? |
We have a Teledyne 3190 Oxygen analyzer in a Glovebox which we use to monitor the oxygen content of the Glovebox.
We do a monthly calibration of the sensor using a He/Ar span gas with 5ppm oxygen. Today I tried to do the calibration on the device and it keeps giving me an error.
During calibration I hook the inlet of the sensor up to a span gas of 5ppm oxygen concentration. I allow the unit to settle. Once the value is settled I press the span gas once and then move the value on screen to 5ppm. When I set the span value to 5ppm, the unit display flashes an error "0000" on screen and does not do anything until I press the span button again. Then it starts flashing "5000" and does nothing until I press the span button again when it flashes "5000" for about 4 more times and then gives a reading. The readings it is giving are completely wrong and the sensor is not able to settle on any value. It seems to be malfunctioning or maybe I am doing something wrong? I think the unit may be broken and we may need a spare.
I'd be very grateful if you could help me out to solve this problem. |
What is the maximum resistive load on the 4-20mA analog output?
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For additional questions, please contact Technical Support.
Q: Is the unit for the oxygen content displayed as "ppm" a volume ratio, a mass ratio or a molar ratio? All three are measured in ppm, but have different values (ppmV, ppmM or ppmn).
A: It is in ppmV. The sensor measures the partial pressure of O2.
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Q: Regarding the 3190 and its RS-232 interface:
1) Is a hard or software handshake used ? (RTS / DTR or XON / XOFF)
2) Is a standard or modified cable necessary ? (Standard cable with Pin 2-3 / 3-2 / 4-6/ 6-4/ 7-8 / 8-7/ 5-5)
3) Is any jumper setting inside of the 3190 ?
4) Which kind of data will be transmitted ? (ASCII signs, values INT,..)
What does the transmission look like ? (Header, Data,- Data length, type, speed)
How can I detect a complete transmission ? (end sign, fixed transmission length, time length)
A:
1) There is no handshake between the 3190 and the PLC
2) Cable has to be pin 1-1 / 2-2 / 3-3 / 4-4 / 5-5 / 6-6 / 7-7 / 8-8 / 9-9 to connect to a regular PC. We only use two pins on the DSub-9 connector on the back panel of the 3190:
pin #2 - Data out of 3190
pin #5 - ground
3) Yes, JP6 and JP7 select baud rate
on = jumper on
off = no jumper
JP6-JP7 - Baud Rateon-on - 1200
on-off - 2400
off-on - 9600
off-off - 19200
4) Data looks something like this:
It is plain ASCII sent every two seconds, and it is on all the time.
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Q: Why is the sensor failure alarm triggered when the Span value (ppm) / Cell output(nA) is over 4.447 ppm/nA?
A: If the unit's microprocessor measures a sensor output that is not reasonable for a given level of O2 during the time of calibration, the failure alarm is triggered.
As an analogy, imagine a bathroom scale. If you put a 100 pound weight on it and it reads 96 pounds, you might think the scale is okay and calibrate it to read 100 pounds. But if the scale read 15 pounds, you might conclude the scale needs replacement.
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Q: On a 3190, what would cause the display to read "0000" and/or "5000" during calibration?
A: After a failed span, the analyzer shows 0000, and when the user presses the span key again, the default value to start adjusting is always 5000.
Just make sure everything is all right and adjust the 5000 value up or down with the arrow keys to the true span gas value.
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Q: How do you retrofit a 3190 from AC to DC power?
A: Please refer to the following instructions: retrofit_3190_3290_AC_to_DC.pdf
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Q: We have a Teledyne 3190 Oxygen analyzer in a Glovebox which we use to monitor the oxygen content of the Glovebox.
We do a monthly calibration of the sensor using a He/Ar span gas with 5ppm oxygen. Today I tried to do the calibration on the device and it keeps giving me an error.
During calibration I hook the inlet of the sensor up to a span gas of 5ppm oxygen concentration. I allow the unit to settle. Once the value is settled I press the span gas once and then move the value on screen to 5ppm. When I set the span value to 5ppm, the unit display flashes an error "0000" on screen and does not do anything until I press the span button again. Then it starts flashing "5000" and does nothing until I press the span button again when it flashes "5000" for about 4 more times and then gives a reading. The readings it is giving are completely wrong and the sensor is not able to settle on any value. It seems to be malfunctioning or maybe I am doing something wrong? I think the unit may be broken and we may need a spare.
I'd be very grateful if you could help me out to solve this problem.
A: You get '0000' after trying a span and the cell output has dropped too low. Therefore it triggers a bad calibration slope, by displaying '0000'. When you press span button again, it starts you at 5000 ppm.
The failure could be the cell is too old therefore the output of the cell has dropped too much, or it could be an electronics problem. But before we get to blame either one, I would like to point out that the manual does not recommend calibrating in the 0-10 ppm range as it is not dependable. I would suggest to retry calibrating on higher concentration. Use air if no other higher concentration is readily available but be warned that it will take a while
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Q: What is the maximum resistive load on the 4-20mA analog output?
A: Maximum resistive load is 500 ohms.
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