Q: List of common CLD issues

1. The ozone lamp will die after many years of service • but along the way, it will begin to decrease its ozone (O 3 ) production and you WILL experience Ozone Starvation (see other FAQ) • The ozone lamp power supply might live long enough to power two or three lamps 2. The Darlington Pair power transistor that controls current to the sensor chip’s Peltier cooler will fail: • sometimes the Peltier chip pulls too much current; • sometimes a technician will unplug and re-plug the Darlington cable and blow the transistor (I’ve done this at least once); • sometimes due to age 3. When reassembling, technicians can cause stress on the ACU02 (the CPU / controller board that sits on top of the BPR [backpressure regulator]) by not routing the ribbon cables neatly; this will break solder connections on some very sensitive chips causing hard failures (digital faults) or the very frustrating intermittent failures. 4. The capillary will foul, causing a loss of sensitivity. 5. The heaters in the reaction chamber are covered with thermite paste; the paste will dry out over time causing poor thermal conduction. This could induce an instability in the temperature control of the "block" (the upper region of the reaction chamber); and this could induce variations in zero, span, and process readings (sample analysis). 6. [later] 7. [later]

Q: How does the 400A work?

The 400A Flame Ionization Detector (FID) THC analyzer tests for the presence and concentration of HC compounds in a continuous gaseous sample by combining the sample with a fuel gas stream, ionizing the present hydrocarbons through combustion, and then measuring proportional charge produced by the presence of the ionized hydrocarbons in the sample.

Q: What is THC?

Total Hydrocarbon (THC) is a measurement of the hydrocarbon content (aggregated, not specific to an individual HC compound) concentration in a measured sample.

Question 1

Won't zero

cms_admin · Accepted Answer

Here's a little background (with respect to mixed fuel analyzers only):

1. When the analyzer is in pristine (new) condition, the zero potentiometer is almost at 10 turns (100%) on the duodial (turns counter). This is where the electronic compensation (for contamination) is at a MINIMUM. Rosemount designed it this was so that turning the pot CCW also caused a decrease in the display value (it’s a little easier for the human brain to comprehend, that is, going CCW causes something to decrease).

2. We release repaired analyzers with the zero pot anywhere from 5 turns (50%) to 9.8 turns (98%); we strive to get the highest reading possible (which implies minimal contamination)

3. RIGAS usually upgrades the 400A Preamp board by replacing the unshielded burner signal wire with a coax (shielded) wire. This helps reduce noise but also makes the signal so clean that we have to install a special potentiometer to inject a small biasing signal. [link to R20 modification]

Here's a little background (with respect to pure fuel analyzers only):

1. When the analyzer is in pristine (new) condition, the zero potentiometer is anywhere between 5 turns (50%) and 8 turns (80%) on the duodial (turns counter). The pure fuel analyzer is WAY more sensitive so any minor contamination easily shows up and needs some zero pot to compensate. 10 turns (100%) is where the electronic compensation (for contamination) is at a MINIMUM. Rosemount designed it this was so that turning the pot CCW also caused a decrease in the display value (it’s a little easier for the human brain to comprehend, that is, going CCW causes something to decrease).

2. We release repaired analyzers with the zero pot anywhere from 4 turns (40%) on up; we strive to get the highest reading possible (which implies minimal contamination)

3. RIGAS usually upgrades the 400A Preamp board by replacing the unshielded burner signal wire with a coax (shielded) wire. This helps reduce noise but also makes the signal so clean that we have to install a special potentiometer to inject a small biasing signal. [link to R20 modification]

When a 400A (or any hydrocarbon analyzer) won't zero, do these checks:

1. Read flame temperature. It should be around 100mVDC.

• if it’s <50mVDC then you're probably running hotter than you should be. Decrease fuel pressure and watch for the change in zero reading.

• if it’s <5mVDC then you're probably running VERY HOT and in danger of melting the Teflon burner jet. Decrease fuel pressure ASAP.

2. Alter fuel pressure to see if a few pounds pressure changes the reading (there will be a change as talked about above but it should be slight).

• if the change is significant, you may have contaminated fuel.

• if the change is significant, you may have the WRONG FUEL. A cylinder of 40% hydrogen / 60% Nitrogen (or Helium) is NOT THE SAME as FID ION FUEL (40% hydrogen / 60% Nitrogen (or Helium)). FID ION FUEL has a cylinder assay where the hydrocarbon contamination is VERY low, maybe even listed as “undetectable”.

3. Alter burner air pressure to see if a few pounds pressure changes the reading (there should only be a MINIMAL change, if any). This statement is null and void if your analyzer is running right at the stoichiometric point such that decreasing pressure affects the actual flame due to oxygen starvation.

• This problem will sneak up on you with an aged analyzer as the air restrictor clogs up over many years of service; you’ll set the air pressure to 15# (per the OEM manual) but the burner won’t actually be getting the prescribed 450 cc/min of burner support air.

• An analyzer running at stoichiometric will be hard to zero and hard to span.

4. Alter sample pressure when flowing zero gas. You should expect some variation in the readings but nothing significant. If the reading does change by a huge amount then sample line contamination is almost guaranteed.

• If your process contains a ‘sticky’ hydrocarbon molecule such as Toluene, then expect significant delay times to achieve a good zero as it will take time for the Toluene molecules to detach from the sample transport tubing walls.

Keywords: Rosemount 400A troubleshooting

Question 2

35K0104R0, NOx Detector 0-800ppm CLD 200 cc/min, Replaces Rosemount 659754 and Tyco 1021326-100-TES

cms_admin · Accepted Answer

If you've stumbled on to this FAQ, you must have a Rosemount NGA-2000 CLD analyzer to measure NOX either dry or wet (referring to the WCLD version). The detector portion of this analyzer is OEM p/n: 659754 (obsolete) and is sold by us under this part number: 35K0104R0. It is the same OEM detector and fully compatible with your NGA-2000 or uCEMS. I'd like to point out that this detector assembly is COMPLETELY repairable and should never be discarded. Here’s why:

1. If the capillary gets clogged:

• Unclog it or solder in a new one

2. If the heaters fail open:

• Replace the heaters

3. If the resettable fuse fails open:

• Replace the fuse

4. If the barrier window gets cracked/busted:

• Replace the window

5. If the temperature sensor goes bad:

• Replace it

6. If the reaction chamber leaks:

• Replace the bad seal (or both seals)

7. If a pin breaks off or a wire opens in the harness:

• Fix the harness

8. If the metal barrel rusts through (this has never happened, but there’s always a first time):

• Replace the housing

9. If the photosensor gets weak or dies completely:

• Replace the sensor

• This is the most challenging aspect as the OEM wants about $8000 for this chip; and, most of the time, it’s the barrier window that gets clouded/stained from the ozone- NO reaction; we don’t change out very many sensor chips.*

10. If the photosensor won't cool down to 1°C, it might be a bad Peltier section of the chip -or- most likely, it's a bad Darlington Pair power transistor (mounted on the aluminum divider panel).

Important: *We’ve been fixing about two of these per year for the past 20 years. Don't listen to the rumors that you can't procure a NGA-2000 CLD detector assembly, we can get them or repair them.*

Question 3

CEMS & Opacity Monitor Field Service Engineer - Experience Required Wooster, OH

cms_admin · Accepted Answer

Company Overview RIGAS (Runyan Industrial Gas Analyzers, Inc.) is a leading provider of environmental monitoring solutions, specializing in Continuous Emission Monitoring Systems (CEMS) and Continuous Opacity Monitoring Systems (COMS). With over 20 years in the industry, we are a partner to a wide range of industries including power generation, petrochemical, and manufacturing. Compensation & Benefits Job type: Full-time, hourly. Wage: $35-$45 per hour. Location Base: Wooster, OH Why should you work for us?

Your typical work week will be 3-4 days on the road and home on the weekends.
You will keep your hotel and airline points to use personally.
You will receive competitive pay and benefits.
Your family and personal time will be respected.
You will be an important member of our team.

Benefits:

Health, Dental, and Vision Insurance (75% Company paid).
Disability and life insurance.
Two weeks paid vacation.
Paid sick time.
Nine paid holidays.
Investment-matching retirement program.
SIMPLE IRA with Company match.
Company provided cell phone.
Maximum IRS mileage reimbursement (for company related travel).
Flexible schedule.
Company credit card provided for work related expenses.
Employees keep their hotel/airline reward points.

Key Responsibilities:

Perform maintenance, troubleshooting, repairs, and audits at customer sites for various process and environmental analyzers such as O2, CO, CO2, O2, NH3, NOx, and SO2 analyzers, as well as opacity monitors.
Troubleshooting and repair will include the disassembly, inspection, replacement and testing of mechanisms and circuitry for failures and defects as well as the determination of repair requirements, obtaining necessary parts, performing necessary functional/operational/compliance testing and documentation.
Perform Federal and Regional compliance audit in the form of: COMS TITLE V audits and CEMS CGAs at quarterly and annual intervals; to include any associated preventive maintenance.
Update parameters of the data acquisition system after maintenance, repairs, and/or audit activities.
Perform installation, startup, and commissioning of CEMS and COMS. Including installation inspection, initial power up testing, calibrations, and U.S. and Regional EPA testing and certifications.
Retrofit, upgrade, and/or replace existing analyzer and monitor systems to Include: sample probes, heated sample line, wiring, tubing, and hardware.
Provide technical support to customers via telephone and digital interface over the internet.
Travel primarily during weekdays. Overnight travel up to 75% is required. Occasional weekend and holiday travel may be required.
Provide support to our repair depot in Wooster, OH when not in the field.

Experience and Skills Required:

Minimum 3 years process gas analyzer, COMS, or CEMS troubleshooting and repair experience on major manufacturer equipment (Teledyne, Rosemount, Procal, Servomex).
Minimum 3 years field service experience.
Two or four year industrial electronics and/or industrial instrumentation degree or certificate, or military electronics or instrumentation schooling.
Knowledge and understanding of 40 CFR 60 and 40 CFR 75 with the ability to communicate requirements to customer personnel.
Strong troubleshooting skills demonstrated in previous jobs including 4-20 mA signal loops and DC circuits. Component level circuit board troubleshooting a plus.
Knowledgeable on gas pressure and flow.
Proficient in use of multi-meters, loop calibrators, valves, regulators, pressure sensors, flow sensors, and the application of additional electronic test equipment.
Ability to read and interpret electrical and flow schematic diagrams.

Other Requirements:

Valid driver’s license and driving history acceptable to the Company insurance carrier.
Able to pass a background check, and drug & alcohol screening, to include frequent customer required tests and random company testing.
Able and willing to climb ladders and work at heights of +200’.
Willingness to work outdoors in a variety of weather conditions.
Clear vision and ability to identify and distinguish colors.
Must be able to lift more than 50 lbs, climb stairs and ladders, kneel, crouch, stoop, and crawl.
Valid Permanent US work authorization, (not requiring sponsorship).

Question 4

List of common CLD issues

cms_admin · Accepted Answer

1. The ozone lamp will die after many years of service

• but along the way, it will begin to decrease its ozone (O₃) production and you WILL experience Ozone Starvation (see other FAQ)

• The ozone lamp power supply might live long enough to power two or three lamps

2. The Darlington Pair power transistor that controls current to the sensor chip’s Peltier cooler will fail:

• sometimes the Peltier chip pulls too much current;

• sometimes a technician will unplug and re-plug the Darlington cable and blow the transistor (I’ve done this at least once);

• sometimes due to age

3. When reassembling, technicians can cause stress on the ACU02 (the CPU / controller board that sits on top of the BPR [backpressure regulator]) by not routing the ribbon cables neatly; this will break solder connections on some very sensitive chips causing hard failures (digital faults) or the very frustrating intermittent failures. 4. The capillary will foul, causing a loss of sensitivity. 5. The heaters in the reaction chamber are covered with thermite paste; the paste will dry out over time causing poor thermal conduction. This could induce an instability in the temperature control of the "block" (the upper region of the reaction chamber); and this could induce variations in zero, span, and process readings (sample analysis). 6. [later] 7. [later]

Question 5

How does the 400A work?

cms_admin · Accepted Answer

The 400A Flame Ionization Detector (FID) THC analyzer tests for the presence and concentration of HC compounds in a continuous gaseous sample by combining the sample with a fuel gas stream, ionizing the present hydrocarbons through combustion, and then measuring proportional charge produced by the presence of the ionized hydrocarbons in the sample.

Question 6

What is THC?

cms_admin · Accepted Answer

Total Hydrocarbon (THC) is a measurement of the hydrocarbon content (aggregated, not specific to an individual HC compound) concentration in a measured sample.

Won’t zero

Won’t zero

How does the 400A work?

What is THC?

35K0104R0, NOx Detector 0-800ppm CLD 200 cc/min, Replaces Rosemount 659754 and Tyco 1021326-100-TES

List of common CLD issues

CEMS & Opacity Monitor Field Service Engineer – Experience Required Wooster, OH