A: If one of our sensors is in a gas composition with H2 as one of the components, and there is O2 present as well, there will be combustion of H2 at the surface of the zirconia sensor running at 720 degrees C. The result will be an equilibrium set up between the resulting O2, H2 and H2O.

If the H2 is small in relation to the O2, there will be little effect on the O2 reading. If the H2 is much greater than the O2, the O2 will be reduced to concentrations in the order of E-22.

Q: What conditions will trigger the alarms on the 9060?

A: The ADC Cal Fail alarm is triggered when any of the reference voltage readings drift outside of their acceptable tolerance. This alarm warns that an analyzer fault has occurred.

An ADC Cal Warning alarm is triggered just prior to the ADC Cal Fail alarm to alert the operator that maintenance is required.

The integrity of the probe reading is assured by measuring the impedance of the zirconia sensor. As the probe ages, the impedance will slowly increase. When it reaches 9k ohm (at 720C) the analyzer will initiate a Sensor Fail alarm. This alarm alerts the operator to arrange to have the probe replaced in the next week or two. The oxygen reading will still be valid.

There are about twenty fault conditions that will trigger the common alarm relay. When the alarm button is pressed, to acknowledge the alarm, the fault condition is displayed on the lower line. If there are multiple alarms, these will scroll on the display as the alarm button is repeatedly pressed.

For more information regarding zirconia probe life expectancy, click here to download the PDF.

Q: How do I cold start a 9060?

A: Cold start procedures can be found here.

Q: I cannot seem to get any signal on the 4-20mA output of the 9060. What do I do?

A: Procedure to check:

Enter the "Set-up" mode and push the "Autocal" button. If a "DAC CAL Fail" alarm appears, than return the instrument for repair. If no alarm is present, than check the outputs with a digital multimeter, in mA mode. If the outputs are there, than the loop must be open circuit (maximum 1,000 ohm).

If the probe or sensor is less than 650C (1200F), than the outputs are driven to 0 mA. Set-up step 91 allows you to deselect this feature.

Q: How can I check for a defective solid state relay in the 9060?

A: Connect a mains voltage incandescent lamp (100W maximum) to the heater output terminals on the analyzer (51 and 52 for probe 1). Turn on the Burner Bypass switch if terminals 18 and 19 are not bridged out. Connect a millivolt generator to terminals 3 (+ve) and 4 (-ve) and simulate 720C, T/C K. The incandescent lamp should be turning off and on in sequence with the heater LED4. If the lamp is continuously on while the LED is flashing, than the SSR has shorted out.

The most common cause of a shorted SSR is a loose wiring connection.

Q: Sometimes I see a symbol (*) and (+) on the LCD of the O2 analyzer, what does it mean?

A: Four symbols periodically flash on the right hand side of the display during normal operation, each indicates that a specific function is currently being performed by the analyzer.

+ = Checking for timed events (30-second interval). Purge and calibration sequences, updates run-time, checks that the BBRAM is okay, reads the ambient RH, updates the O2 value of the reference air with respect to the RH value.

* = The heartbeat means the software is running correctly (1.5-second interval).

# = Auto-calibration of the analyzer's electronics with respect to the four reference voltages (60-second interval).

Z = Sensor Impedance Check (24-hour interval when the impedance is normal, at 11:30pm; 60-second interval when the impedance is high).

Q: What are the factors that affect the life expectancy of Teledyne's zirconium oxide probes?

A: The deterioration of a zirconium oxide probe is of interest to engineers to maintain instrumental reliability. The degradation does not follow a predictable formula.

Background

Zirconia probes are the most common method of controlling combustion and heat treatment processes. Teledyne has hundreds of systems installed in power stations, petrochemical plants, heat treatment and annealing furnaces, incinerators, cement plants and drying ovens. ?ll these process have different requirements, and pose different conditions to the components of the probe.

Failure Modes

The useful life of the probe is limited by the first component of the probe to fail. The failure may be a slow deterioration or a sudden change of the working condition of one of the vital components.

Components that may have a sudden failure rate are:

The heater in heated probes (open or short circuit)

The thermocouple (typically goes open circuit)

Out Metal Sheathing (breakage through corrosion or abrasion)

The ceramic components of the probe (physical or thermal shock)

Components that will slowly deteriorate are:

The electrode coating of the zirconium sensor

The thermocouple (corrosion, grain growth)

Internal electrode and thermocouple wires (corrosion, grain growth)

Out of all these component failures, only the zirconia electrode material loss can be measured in an attempt to determine the remaining life of the probe. This failure can only be predicted with the experience of the process it is being used in.

The analyzers measure the impedance of the zirc sensors automatically. Without interfering with the process measurement, the analyzer allows an operator to read the impedance measurement and will automatically raise an alarm if the impedance is high enough.

There is no definite impedance at which a sensor can be said to have failed. ?s the electrode deteriorates, the impedance will rise. However the sensor O2 reading is not affected by the loss of electrode material over a wide temperature range over a wide range of impendence (up to tens of kilo ohms). In fact, if the temperature of the sensor is over 850C the sensor will read the correct O2 concentration without any electrode material as long as there is no other deterioration of the electrode connections. The response tie will usually increase as the electrode ages.

The sensor impudence is the sum of the electrode impedance and the electrolyte impudence. The electrode impedance is the part that will increase as the probe ages. Complicating the interpretation of the sensor impedance measurement is the electrolyte impendence will be markedly lower at higher sensor temperatures.

As an indication of probe life, the TAI analyzer will raise a sensor fail alarm when the sensor is over 9k ohms when the sensor temperature is 720C.

Q: How do I know when to replace the sample pump on the 9060H?

A: The normal flow range from a CM-15 pump connected to an oxygen probe is 100 to 120 cc per minute. The zirconia sensor will work properly with a reference air flow rate as low as 10 cc per minute.

The common mode of failure for the CM-15 is a worn phosphor bronze bearing eventually causing the motor to "pole out" thereby greatly increasing the current drain. The 9060 analyzer monitors the current consumption of the pump and will raise a "Reference Air Fail" alarm if the current consumption exceeds a set level (250mA). The alarm is also raised if the current falls below a set level (15mA) if the pump goes open circuit or is unplugged.

Q: How is the offset of a 9060 Zirconia Sensor determined?

A: A sensor's offset is determined by running the probe with ambient air on both sides of the cell. With the same oxygen level on both sides of the cell with the sensor heated to 720C the theoretical offset should be zero.

The mV offset value measured with 20.95% oxygen on both sides of the cell is the value that should be programmed into the analyzer. Each probe has the offset value (and impedance) on the sticker near the serial number.

Q: If I set the probe offset to a default value of 0.0mV, what is the worst case O2 measurement error that can result?

A: If the offset was high, in the range of +/- 2mV, than at a 2% oxygen level the reading would be between 1.82% and 2.19%. I doubt this error would be detrimental to operating conditions.

Q: Is the 9060 sensitive to change in pressure? What is the maximum pressure for the probe?

A: If the reference air and process gas are the same pressure, than the readings are unaffected. The percent of volume remains the same. If there is a difference in the flue gas and ambient air pressures, than the analyzer can compensate the reading by entering the flue gas pressure options in set-up steps 34 to 38.

The maximum pressure is ~2.5 atm (250 kPa).

Q: What is the voltage of the lithium back-up battery on the main board for the 9060 transmitter's RAM and real-time clock? ? Why can we not get any voltage value by measuring it?

A: The BBRAM / real-time clock is an internally powered device. The battery backup for the RAM is within the internal circuitry of the module and cannot be measured.

Q: The value of O2 being reported by my unit seems wrong. What might cause an erroneous reading?

A: Check the reference gas flowrate. The reference gas flowrate needs to be between 0.1 to 0.5 liters per minute. If it is outside of this, significant errors can result in the O2 reading. Also check that the sample flow rate is between 5 to 10 liters per minute.

Q: What are the specification of the cable required to connect O2 display and calibration unit with 9060H probe?

A) Black - KP +ve Extension grade 24 / 0.20
B) Brown - 24 / 0.20 Copper
C) Orange - 24 / 0.20 Copper
D) White - 24 / 0.20 Copper
E) White - 24 / 0.20 Copper
F) Blue - KN -ve Extension grade 24 / 0.20
G) Green / Yellow - 24 / 0.20 Copper
H) Tinned Copper braid 75% 0.20 mm
J) Black - PVC 105C

Q: Does the 9060H probe have a shelf life?

A: No. The sensor within the probe is mechanical, not chemical, and therefore does not expire.

Q: I was told that in-situ zirconia-oxide oxygen analyzers actually measure NET oxygen in the flue gas. That is, any unburned hydrocarbon or CO in the flue gas is oxidized to H2O and CO2 via the catalytic action of the zirconia-oxide cell. The net result, I was told, is a reading of net oxygen AFTER all combustibles are oxidized to CO2 and H2O, assuming that the flue gas has excess oxygen.

Is the comment above concerning net oxygen correct?

A: If there are hydrocarbons present in the gas being measured then these will react with any available oxygen at the catalytic surface of the sensor. The operating temperature of the sensor is 720C. This results in a low oxygen reading.

Q: Do you have a service manual for the 9060?

A: Yes. Please refer to the following document: 9060_service_manual.pdf

Q: We use 9060H O2 analyzers and connect them to our PLC system to perform O2 trim functions on boilers. We are doing an installation in a very large boiler and we have a question on the wiring restrictions. We connect all the O2 sensors in the stack back to a central panel to read the O2 signal, Temperature signal and control the heater. Is there a maximum length of cable that we can use to run from our central panel to the O2 sensor? Is the length dependent on the gauge of the cable?

A: The maximum that we recommend is 50 meters (164 ft) is but there are some sites that have cable runs up to 100 meters. The signal to noise ratio is our concern with long cable runs.

Use One pair of 1.5mm2 for the heater power, one pair of screened copper for the sensor signal and screened type “K” compensation lead wire for the thermocouple.

Q: We installed a 9060H and after installation an alarm LED lights up in front of the indicator on the center key. How can we reset this?

A: Push the alarm button once to see what the alarm is and push it again to acknowledge the alarm. The light will go to a steady state after acknowledging and will disappear when the alarm condition ceases.

Q: How can the display on the Teledyne 9060 transmitter screen get brighter? Is there a contrast or brightness adjustment?

A: No, there is no brightness or contrast adjustment.

Q: What is the size and kind of thread on the hole in the sensor head? We have to use a thicker cable and have to replace the original compression fitting with direct cable gland.

A: The thread that the conduit adaptor or electrical connector screws into is 7/8"UNEF.

Q: What is the start-up procedure for the 9060H analyzer? 

A: Attached is the start-up procedure for the 9060H: 9060-Start-up procedure.pdf

Q: What if the keyboard does not respond to any key presses?

A: There is a two position switch on the door board (top LHS with the door open). If the switch is in the UP position then the keypad is disabled and should be switched downward to enable it.

Q: When auto-purge is enabled, the ‘Probe Filter Acc” alarm is active and the Alarm LED flashes. How can this be defeated so the purge does not trip this alarm?

A: This can be defeated by jumpering terminals 12 and 13

Q: When Analyzer 9060L displays the error message 02, What the tests we can make to know what is wrong in the analyzer ?

A: This message is displayed when the input voltage to the ADC rises above the upper limit of the ADC. This could occur if the probe is exposed to zero oxygen concentration, making the Percent Oxygen Analyzer output of the sensor higher than the top scale of the ADC. It may also occur if the thermocouple should open. If not exposed to Nitrogen with nearly zero O2, then maybe the thermocouple connections should be checked.

About Us

Founded in 1964, Teledyne Analytical Instruments manufactures gas and liquid analyzers, sensors and custom integrated analysis solutions. This includes hazardous area solutions meeting current NEC, ATEX and IECEx standards. TAI has an ISO 9001 certified quality management system in place.