General Calibration
Each oil has a specific response factor to fluorescent light. Therefor, calibrating against your target oil is recommended for best results. For example, if your sample is produced water, you will want to prepare your calibration solution with site-specific crude oil.
The answer is illustrated in the Linear Calibration screen. After calibration, you will need to check the linearity. As an example, if you calibrated the instrument to 100 ppm, to verify the linearity, you should dilute the 100 ppm standard solution by half, and see if it reads about half. If not, the 100 ppm is not linear, and you need to recalibrate with a lower concentration calibration solution.
If your 50% dilution reads about half, but your 200 ppm standard solution reads low, it means that your linear range is between 100 and 200. You can make standard solutions between 100 and 200 to learn the actual linear range.
If your 50% dilution reads about half, but your 200 ppm standard solution reads low, it means that your linear range is between 100 and 200. You can make standard solutions between 100 and 200 to learn the actual linear range.
The CheckPOINT™ is a solid standard, which allows you to verify calibration without preparing standard solutions. Your first calibration must be done with liquid standard solutions. After the initial calibration (and you have verified the linearity of your calibration curve), insert the CheckPOINT™ and follow your manual’s instructions for making readings and adjustments. Use the included Allen wrench to adjust the screw. We recommend setting the reading in the second half of your calibration range.
Under normal and recommended operating conditions, the monitor will display negative measurements when no water is present. The reason for this is that the air present in the flow cell without water has less background fluorescence than water. This is a normal situation; however, the analog output, which will be 4-20 mA, will be limited to 4 mA or 0 ppm, if so programmed, even when no water is present. Thus, the remote indication will be 0 ppm in the event of no water flow.
The monitor will also display negative numbers if the measurement is less than the value of the blank. Although negative concentrations are only theoretical, a display of a negative concentration is very important diagnostic information for our monitor since fluorescence is never measured from an absolute zero, but in reference to a defined zero. Thus, a negative measurement in the presence of water indicates that the defined zero, which the customer selects, is not appropriate. If the display was truncated to zero, this situation, which will occur in water obtained from natural sources, will never be detected. It could also cause false measurements from the monitor if not corrected.
In most applications, the online monitor or laboratory analyzer can display measurements according to a certain regulatory measurement method results if a correlation is developed between samples measured by our equipment and the regulatory measurement method. Our manuals have instructions on how to develop the correlation calibration.
TD-500D
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EPA 1664A is a gravimetric method, and the procedure requires evaporation of solvent. During the evaporation process, some oil compounds evaporate along with the solvent, resulting in lower readings. If EPA 1664A is the standard method you need to comply to, correlation is the key. Any two different methods will produce different numerical readings. Measurements from a TD-500D/TD-3100 can be well correlated to the EPA method. After the correlation is in place, the TD-500D/TD-3100 can consistently predict results from an EPA lab.
Yes, because the TD-500D is battery powered, it can be operated anywhere.
No, the TD-500D is not intrinsically safe; however, because samples are brought to it for analysis, the TD-500D is typically operated in laboratories or other general purpose areas.
The TD-500D can typically make well over 1000 measurements with a set of batteries.
No, the TD-500D uses four standard type AAA alkaline batteries.
No, we do not recommend using rechargeable batteries in the analyzer since they may leak or damage the analyzer.
Turner Designs Hydrocarbon Instruments or our local dealer will evaluate your application and advise the recommended cuvette type. In some cases you may be recommended to have both sizes of cuvettes to determine which cuvette type is best for your application.
No, the TD-500D is not sensitive to BTEX compounds. If BTEX compounds need to be measured, then our TD-3100 Laboratory Fluorometer can be used.
No, the TD-500D is not sensitive to aromatic solvents, gasoline, kerosene, jet fuel, or low concentrations of diesel fuel. Our TD-3100 Laboratory Fluorometer can be used to measure these fuels and solvents.
We do not recommend the TD-500D for measuring low concentrations of lubricating oils in water because it is not sensitive towards these oils. We recommend our TD-3100 Laboratory Fluorometer for these applications. High concentrations of lubricating oils in water possibly could be measured by the TD-500D, but the TD-3100 is a better choice because it can also measure low concentrations of most lubricating oils.
No. In general, the No Solvent Method is not sensitive enough to be used for measuring refined petroleum products on the TD-500D. The exception to this is #6 fuel oil, also called Bunker C or heavy fuel oil. The No Solvent Method is designed for typical black crude oils.
When evaluating the calibration on a TD-500D, you need to evaluate the sensitivity as well as the linearity. The sensitivity is displayed on the diagnostic screen as the value of the %FS-Std. As long as the %FS-Std is greater than 2, the sensitivity is sufficient for the calibration. You should also check the linearity of the calibration. This is easily done by measuring a diluted calibration standard. A measurement close to the expected diluted concentration will confirm linearity.
If the signal from the calibration standard exceeds the allowed measurement of the TD-500D, then this message will appear. You can correct this by A) calibrating at a lower concentration, and/or B) using a smaller cuvette size, and/or C) switch to a less sensitive measurement channel.
A %FS-Std less than 2 indicates that the calibration solution has insufficient response for reasonable measurements. To increase the response, you can A) calibrate at a higher concentration, and/or B) use a larger size cuvette, and/or C) switch to a more sensitive measurement channel.
TD-3100
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Yes, the TD-3100 by itself does not have the optical kit installed. Various optical kits for measuring different ranges of hydrocarbons are available.
Turner Designs Hydrocarbon Instruments or its local dealer will recommend the appropriate optical kit for your application if we are provided with the application details. In some cases multiple optical kits may be recommended.
Yes, there is a unique lamp for each optical kit.
The TD-3100 comes with a power adapter that converts AC power to DC power. A standard 12 VDC car battery cannot be used to power the TD-3100 without the use a voltage regulation device between the battery and the TD-3100.
For most applications, the TD-3100 can be initially calibrated with a calibration solution. Then the CheckPOINT™ Solid Standard can be set to a response similar to calibration solution. Subsequently, the TD-3100 calibration is checked with the CheckPOINT™ Solid Standard and, if needed, recalibrated with the CheckPOINT™ Solid Standard.
Although the possible %Sens value can range from 1 to 99, practical measurements and applications will produce %Sens values between 4 and 70.
A message of maximum sensitivity during an attempted calibration means that the TD-3100 reached the maximum sensitivity without the calibration solution producing sufficient measurement. Usually this happens when trying to calibrate either with a calibration solution that does not fluoresce or a calibration solution that is not suitable for the optical configuration presently being used in the TD-3100. A condition of the lamp not being installed properly can also produce this symptom. Please check the optical configuration and/or lamp.
There can be two causes of this problem. A) The blank that was introduced into the TD-3100 may have been contaminated. In this case, try recalibrating with a blank that is known not to be contaminated. B) If the response of the calibration solution is quenched or beyond the practical measurement range, then this symptom can occur. If dilutions of the calibration standard produce greater fluorescence response than the calibration standard, this is evidence of quenching. If quenching is occurring, you can calibrate at a lower concentration, use the attenuator plate(s), and/or change the optical configuration.
You should first check that the optical filters are correctly installed. The excitation optical filter must go in the excitation filter location. The emission optical filter must go in the emission filter location. If you reverse the filters, a value will produced by the TD-3100, but that value will be the same for all concentrations. Also, you should check that the optical configuration is suitable for the hydrocarbons you wish to measure.
Yes, they do because they are affected by humidity. You should operate your TD-3100 in a location with humidity control. If you need to store the TD-3100 for a long period of time, we suggest you remove the optical filters, place them in their original container, and store them in a location with the lowest humidity possible. The optical filters are considered long-term consumable items.
The No Solvent Method was originally designed for the TD-500D Oil In Water Analyzer. You may be able to use it on the TD-3100 if you use the cuvettes and cuvette adapter for the No Solvent Method and are using the crude oil optical kit. The No Solvent Method cannot be used to measure refined petroleum products or gas condensates on the TD-3100.
We recommend that the cuvette be rinsed twice with the new solution to be measured and then be filled up a third time for the actual measurement. Rinsing twice will flush out any previous solution remaining in the cuvette.
TD-4100XD and TD-4100XDC
The E09 TD-4100XD and E09 TD-4100XDC have four alarm relays that you can configure with the monitor keypad. You can control which alarms report to each relay, with the capability of having multiple alarms report to the same relay. Each relay has terminations for both normally open and normally closed signals. We recommend that you set the monitor’s System alarm to report to at least one alarm relay.
Although the E09 online monitors allow for nonlinear calibrations, with more than two calibration points, for most direct calibration applications it is generally not necessary to use more than two calibration points. More than two calibration points would only be needed if you know that the calibration range is nonlinear.
Yes, this is possible.
There are two points to this answer: A) The linear or dynamic range and B) The maximum fluorescence measurement capability of the monitor.
A) Unless you are specifically using a nonlinear calibration, you want to limit the measurement range of the monitor to the linear range where change in fluorescence is linearly proportional to concentration. The linear range varies depending upon the monitor parameters, monitor configuration, water source, and hydrocarbon type; however, Turner Designs Hydrocarbon Instruments generally configures the monitor to operate in the linear range for your application. If your application involves measurement over a dynamic range, then a nonlinear calibration is necessary. The absolute limit of the monitor would be the dynamic measurement range.
B) Measurements are also limited by the maximum fluorescence measurement capacity of the monitor, which for the E09 series is 10,000 RFU (relative fluorescence units). If a measurement is beyond 10,000 RFU, then OVER is displayed on the monitor’s screen.
Should this situation happen, the displayed concentration measurement will decrease as the concentration increases.
This situation is common. Turner Designs Hydrocarbon Instruments configures its monitors to avoid situations like this, but it is possible in certain applications or situations. The decrease in fluorescence measurement (concentration) is caused by the light entering the sample but not being able to uniformly penetrate it. This situation is also called quenching. Extreme situations may cause negative measurements. Because this phenomenon can happen over extremely wide concentration ranges, Turner Designs Hydrocarbon Instruments does not recommend a monitor for applications where the concentrations can momentarily range from low ppm to percentage levels of hydrocarbon in water. Indeed, we are not aware of any measurement technologies that can linearly measure from ppm to percentage levels of hydrocarbons in water.
If the described situation is a possibility, Turner Designs Hydrocarbon Instruments recommends that you set your concentration alarm(s) to the latched mode. The monitor will stay in alarm until someone goes to the monitor, visually or otherwise inspects the water sample, and then releases the alarm by pressing a key on the monitor.
For a direct calibration of an E09 online monitor, the blank water should be the same water as would normally be monitored, but should not be contaminated with the hydrocarbon(s) to be measured. This is because all water sources, regardless of hydrocarbon contamination, have some background fluorescence. Unless your monitoring application involves normally measuring deionized water or distilled water, these water types should not be used as a blank because they will have lower fluorescence backgrounds than other water sources.
How do I know what to use for blank water in a direct calibration application for an online monitor?
The blank water should be the same water type as what would normally be monitored. The blank should be the same water used in your process, before the chance of contamination. For example, in a closed-loop cooling system, the blank water would be the make-up water for the cooling system. As another example, for an open-loop cooling system, the blank water would be the cooling water before it enters into the system where contamination can occur.
There are two main factors which affect how often a monitor should be recalibrated: monitor conditions and process conditions. The monitor has a built-in closed loop calibration system that maintains the monitor’s measurements within a variation of 10% or less over six months. However, the lamp is changed every six months, so the monitor should be recalibrated every time the lamp is changed. The process water that the monitor is measuring can also change over time, such as a changing fluorescent background. If the fluorescent background changes significantly relative to the measurement range of the monitor, then a recalibration should be performed to account for the background changes. This may require recalibration more frequently than each time the lamp is changed.
Yes, there is an easy way to check this. Each monitor has a CheckPOINT™ Solid Standard that is set to a particular value during the calibration or recalibration. If the monitor’s measurement of the CheckPOINT™ Solid Standard is within a tolerance range of the original measurement of the CheckPOINT™, then any drift in the water measurement is likely do to changing process conditions or hydrocarbon contamination. If the CheckPOINT™ measurement is outside of a tolerance range compared to the original measurement, then the drift is likely due to the monitor, such as dirty optical windows.
The CheckPOINT™ Solid Standard is not generally used for calibration of the monitor, although in rare cases it could be used. Rather, it is used as a diagnostic tool for personnel operating the monitor. For example, if the monitor has some reading that you want to validate, you can insert the CheckPOINT™ Solid Standard into the monitor and the CheckPOINT™ Solid Standard will validate the monitor’s measurement. The CheckPOINT™ Solid Standard can diagnose low measurements that would be caused by dirty optical windows. It can also diagnose someone inadvertently affecting the calibration of the monitor.
A low measurement of the CheckPOINT™ Solid Standard relative to the set value usually indicates dirty optical windows. You should clean the optical windows and then measure the CheckPOINT™ Solid Standard again. If the measurement of the CheckPOINT™ Solid Standard returns to its normal range, then the problem of dirty optical windows has been corrected. Note that dirty optical windows can indicate problems in the sample flow system or operation of the sample flow system, so these should be investigated.
This is a common question. The answer is not necessary a specific number of sample points, but rather quality of the group of sample points. Turner Designs Hydrocarbon Instruments recommends that the concentration span of the sample points be more than 50% of the desired measurement range of the monitor. Furthermore, Turner Designs Hydrocarbon Instruments recommends that the correlation coefficient of the predicted calibration equation be 0.8 or greater (1.0 indicates perfect fit). Ideally one would want many points equally spread out over the desired measurement range. Practically, you probably would not want to use less than five points.
No, this is not a problem as long as you know that the sample points do not adversely affect the linearity (or nonlinearity) of the calibration equation. In some cases it may be necessary to use points outside of the range to establish a good correlation calibration. On the other hand, due to the possibility of nonlinearity, it would not be wise to use a sample far outside of the measurement range, e.g., use a point at 2000 ppm when the normal measurement range is 0 – 50 ppm.
If your monitor is normally measuring the outlet of a treatment process, consider adding a sample line to the monitor with a valve from the inlet of the stage of the treatment process. With this arrangement during the calibration, the flow of sample from the inlet and outlet of the treatment process stage can be blended together to create varying concentrations. This arrangement allows the calibration to proceed very quickly.
Almost always the problem is caused by insufficient air pressure provided to the monitor. The AVS actuator requires 60 psig minimum air pressure and, ideally, 80 – 100 psig. Insufficient air pressure may cause the valve to open slowly or not at all, preventing a smooth falling stream in the flow cell.
When no water is flowing through the flow cell, the monitor will typically read less than zero concentration because the empty flow cell has less fluorescence response than the blank water.
While this sounds like a great idea and can produce a calibration with excellent correlation, the calibration equation produced by this situation will not correspond to reality for monitoring produced water. In other words, the resulting calibration equation will be incorrect and can produce very large errors. This situation occurs because tap water and distilled water have a very different fluorescence background than produced water. This is also the reason you cannot simulate produced water by adding crude oil into tap water, distilled water, or even sea water.
For a short term fix, you can stop the flow through the monitor, remove the flexible hose, and brush it out with the smallest cleaning brush. You should also brush out the flow cell nozzle and then clean the optical windows. For a long term solution, you may want to consider a clean-in-place (CIP) system for the monitor.
This is a very good question. There are several factors to consider such as difference in fluorescence response between different hydrocarbons and likelihood of leak of a particular hydrocarbon. If one hydrocarbon has a 95% probability to be present and another has only a 5% probability, then Turner Designs Hydrocarbon Instruments will chose the hydrocarbon with the 95% probability. If the probability is unknown or assumed to be equal, then Turner Designs Hydrocarbon Instruments will chose the hydrocarbon with the least fluorescence response per unit concentration to provide the most conservative measurement. In some cases where the ratio of the responses of various hydrocarbons is very extreme, the latter method may produce considerable false positives.
Yes, this is important because Turner Designs Hydrocarbon Instruments’ monitors are configured for specific applications. Configuration changes may be necessary to allow the monitor to work in the new application. For example, the optical configuration may have to be changed. Turner Designs Hydrocarbon Instruments’ Service Department can help you with the new application.
