Frequently Asked Questions
Here are the most common questions we're asked about BWB Flame Photometers. If you can't find the answers you need here, get in touch and we will try to get your questions answered quickly.
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Yes, all elements can be calibrated at the same time using single or multiple calibration standards.
Can I calibrate all elements at the same time?
Calibration correction allows you to correct a calibration curve using just a Blank and/or the highest point within the curve. This helps to correct for drift.
What is calibration correction?
Drift can occur over the period of a day as environmental factors such as air temperature, humidity and barometric pressure change. The instrument employs the use of a live flame; a flame is affected by all of these factors and more, for instance, a higher humidity level means less oxygen in the air.
What is drift in relation to a calibration curve?
Multiple factors can cause drift, just a few include; air temperature, environmental pressure and humidity, sample head.
What causes drift?
This is the distance from the nebuliser to the top of the liquid sample being analysed. As the head increases the sample flow rate (aspiration rate) will decline marginally, it is strongly recommended to sample from broad sample cups rather than tall and narrow sample cups. We provide 100 disposable cups with every instrument to get you started and offer them for sale straight from stock.
What is meant by sample head?
This can be found in the technical data for the particular model, we suggest that in all cases, in order to maintain most consistent results and prevent a requirement for increased cleaning, you keep all concentrations presented to the flame below 100ppm. This can be achieved by calibration and sample dilution.
What is the detection range for each element?
In the majority of our models you can calibrate a curve with up to 10 points, in our BIO range (BIO, BIO-AV & BIO-943*) you can calibrate with up to 5 points of calibration. In both cases this excludes the Blank.
*USA market only
What is the maximum number of calibration points for a multi-point calibration?
All of our instruments include a gas detection module that detects (by ‘smell’) a gas leak, this is far more sensitive than the human nose and can alerts you to small weeps that may otherwise go un-noticed. We also include flame detection via infrared analysis, safety gas cut off and low level detection in the waste cup*
*Not included on the Flash instrument range
What safety features are present on the instrument?
We offer the ability for gas adjustment in order to fine tweak the flame to set it to the optimum level, the average gas consumption rate is 0.155 Litres per minute.
What is the gas consumption rate and can it be adjusted?
We supply everything you need to use the instrument straight out of the box, excluding the gas. You can find a full list of everything included under the ‘in the box’ section on each product page. We supply all of the calibration standards relevant to the elements within each instrument and offer them ex-stock available for purchase to replenish your supplies.
What reagents do I need to purchase?
Yes, this is fitted to the instrument and we supply a gas hose (conforming to UK standards) to connect your gas source to the regulator, the regulator can be supplied with a maximum of 16 BarG.
Does the system come with a gas regulator?
There are quite a few differences between Flame AES and Flame AAS. Both introduce the ions into the flame where they are put in an excited state. With FES (also known as AES), as the excited state "relaxes" it emits light of a specific colour which is then detected. The more light detected the more ion is in the sample. With Flame AAS, the excited state will absorb certain colours. A white light containing all colours is passed through the flame and the excited ions will absorb certain colours. The degree of absence of those colours is a measure of the concentration in the sample.
What is the difference between Flame AAS and Flame FES?
Yes we do, our BIO instrument is supplied with mmol/L calibration standards, alternatively, these can be purchased individually or as part of a kit.
Do you have calibration standards in mmol/L ?
Multiple the mmol/L value by the atomic mass of the element, for example Lithium (Li) has an atomic mass of 6.94, if we had 10mmol/L of Li, this would equate to approximately 69.4ppm.
How do I convert mmol/L to ppm
It depends on what stage of the process you wish to measure. The actual biodiesel cannot be run through the flame photometer. However, if you’re interested in the waste portion to ensure that the Na & K have been fully flushed out then this would be possible. Many of these soap-like compounds are washed out with water, as long as the measurement is conducted towards the end of the final wash then analysis should be ok. Conducting the analysis too early through the wash period could lead to the soap-like compounds forming foam inside the mixing chamber and affecting the instrument stability.
Can we measure Na & K in Bio Diesel using your instruments?
Yes we do, we supply paper copies of all certificates of analysis with each of our calibration standards, in addition, further copies can be downloaded on demand from our online portal or customer portal.
Do you supply certificates of analysis with calibration standards?
You can download these from our website or though our customer portal.
How do I get copies of the calibration standards certificate of analysis?
Our specifications are designed to give a comparative assessment against competing brands, and allow for a variety of applications and methods of analysis. In some cases it is more than acceptable to sample solutions containing greater than 100ppm. We suggest, however, that samples are kept below 100ppm for 2 reasons:
1. Higher than 100ppm and the interferences between ions starts to become significant. This will throw off the results or will require matrix corrections when calibrating.
2. High concentrations of salts will build up in the mixing chamber/burner where they can come off sporadically causing an unstable signal. This then requires those parts to be cleaned very often, possibly several times a day, which is not very desirable for the user.
Why do your specifications state limits of analysis greater than your 100ppm recommendation?
Everything you mention about the environmental situation will affect the stability from air temperature to humidity and barometric pressure. Na will be the worst because there is a lot of Na in smoke, dust, exhaust and hair. The K is not quite as prevalent in the environment as Na and Li is not at all.
What environmental factors can affect the stability?
We strongly suggest using propane, typically most industrial grades are acceptable and a clinical grade is not required. Butane, however, is most preferred when conduction sample analysis for Barium only. All of our instrument from 2019 allow the operator to select the gas source from a choice of propane, butane and methane (natural gas / town gas) without any modification.
What is the recommended gas to operate a flame photometer?
Yes, you have the option of configuring the system to show a maximum of 1, 2 or 3 decimal places per element and each element can be configured differently. The decimal point will then auto range to your maximum setting based on the value of the sample. The ranges are as follows:
Can I change how many decimal points are displayed?
Yes, all of our instruments allow for the operator to change the units of measure, the units will be updated on the next calibration. Please note that the instrument does not carry out any calculation when changing from one set of units to another, it is merely for display. The units can be selected from the following list:
Is it possible to change the units of measure?
Yes this will not be a problem. It’s important to ensure that your calibration standards are also prepared to reflect this content so that accurate results are achieved.
Can I use samples containing 0.1mL per Litre of sulphuric acid?
No, we do not suggest this due to the wetted materials. HF will cause irreparable damage to these components and even when used in small concentrations damage will occur over time. The use of HF voids any warranty.
Can I use samples containing Hydrofluoric acid (HF)?
Yes, the instrument will store a calibration until the user deletes or overwrites it, in addition you can export the calibration data to a .csv file using our PC software, supplied free of charge with every instrument.
Can I save a calibration curve?
Yes, the instrument will remember your calibration data until your delete or overwrite it.
Does the instrument remember the calibration data?
Yes, the instrument has a built in storage facility for samples results up to 200 (but this maximum can be configured by the user). You can also use the PC software, provided free of charge with every instrument to export the results to .pdf or .csv reports.
Does the instrument remember sample results?
This varies and we cannot provide an exact answer, there are so many different variables that have an effect on flame stability that every application will be slightly different. However, we offer the ability to carry out a calibration correction (using just the Blank and maximum calibration point) to adjust the curve to the conditions at that time. This speeds up the process of keeping a calibration at its most accurate.
How often do I need to carry out a calibration?
Yes, all flame photometers require a period of time to reach thermal equilibrium. The exact time will depend on the conditions of the local environment. On average if the ambient is approximately 20°C then we suggest a period of 20-40 minutes for warm up.
Does the flame photometer require a period of warm up before it is used?
Yes, the BWB-XP is ideally suited to be used with waters from lakes, streams, rivers, and lagoons. Depending on the concentrations of the ions the samples will probably need to be diluted for the measurement and the reading then multiplied by the dilution factor to get the final result. The ranges for each ion are:
• Na= 0-1000ppm
• K= 0-1000ppm
• Li= 0-1000ppm
• Ca= 10-1000ppm
• Ba= 30-3000ppm
However, BWB Technologies do not recommend that routine measurements be used at the higher concentrations. For the best results the samples should be diluted so they are around 100ppm or less.
Can I use the instrument for analysis of all 5 elements in water samples from natural environments?
Matrix is the set of all the species that are present. Some of them we want to measure, some of them interfere with what we want to measure, and some of them are in the background that may or may not affect our results. For example, Wine samples have alcohol present in them, we know that alcohol will affect the flame which in turn affects the results so we have to add alcohol to our calibration standards to help ensure the standards have a similar matrix as a sample and therefore behave in a similar manner within the flame.
What does the term ‘Matrix’ mean?
Yes we do, we include a bottle of ‘Diluent Concentrate’ with all of instruments, and additional bottles can be purchased when required.
Do you recommend the use of a surfactant?
This is a surfactant and lowers the surface tension of the fluid to aid in the atomisation of the sample.
What is the purpose of Diluent Concentrate?
The use of a surfactant helps to lower the surface tension of the fluids, this aids the atomisation process of the fluid and creates a finer and more consistently sized mist in the mixing chamber. You can therefore expect a greater ratio of sample making it to the flame in a more consistent patterns giving more accurate and stable results.
Why should I use a surfactant or Diluent Concentrate in my analysis?
We do not use a water separator nor do we need one with our BWB-XP flame photometer. Other makers use a much higher air pressure with an external compressor and do need the water separator. Our compressed air is much lower in pressure and does not have the issue of water ‘falling out’.
Do you specify the requirement of a water separator like other flame photometers do?
We think so, yes. We also have many clients all across the globe that have done exactly this and are more than happy with the new modern instrument.
Is the BWB Flame photometer a good replacement for the IL 943 (IL943)?
This depends whether you’re analysing the sample using manual methods or with our Automatic Fluid Handling System (AFHS) and whether or not you’re conducting Auto-Dilutions. For our stand alone instrument used in manual mode we suggest 3mL of sample, with AFHS that increases to 5mL and where a sample is diluted using our automatic diluter as part of the AFHS then the final volume needs to be 5mL, so if diluting 100:1 you would need 0.05mL of sample. That being said, there are practical limitations too, for instance 0.05mL in the bottom of a sample vial would be difficult for the cannula to extract and so 0.5mL would be suggested in one of our 1mL sample vials. If you have a particularly small volume of sample, please get in touch and we can offer further advice and guidance.
How much sample do I need for analysis?
The highly concentrate calibration standards we provide have a 2 year shelf life from point of manufacture. We never supply calibration standards with less than 6 months shelf life. Typically most calibration standards are supplied with 12-23 months of shelf life.
How long do calibration standards last?
Yes, we provide what we call a RAW value, this value represents the analogue to digital conversion of the signal strength at a point in time, the higher the RAW the greater the signal strength. We use the RAW as a figure to create calibration curves and record results. The RAW is displayed and you can use this to create your own graphs.
Does the instrument provide any reference for me to create my own calibration curves independent of the instrument?
Yes, all of our instruments can be configured for Process Control and some come as standard configured for this application. The instrument can monitor and sample a continual flow 24/7 if so required. Contact us for the full brochure.
Do your instruments allow for continual sample analysis from a pipeline?
No, the use of acetylene gas will cause a hazardous and very dangerous situation, leading to the possibility of explosion and catastrophic equipment failure. This would not be covered under warranty.
Can I use acetylene gas to increase the flame temperature?
No, the use of oxygen will cause a hazardous and very dangerous situation, leading to the possibility of explosion and catastrophic equipment failure. This would not be covered under warranty.
Can I use oxygen as a secondary air source?
Multi-point calibrations can be used in all cases and is recommended where greater precision is needed. Single-point calibrations should only be carried out when the concentrations of the samples are at or below those stated in the Operating manual. For example if measuring Na at around 20ppm it would be acceptable to carry out only a single point calibration, however, if you have a range of sample between 0-20ppm then a multi-point calibration would enhance your accuracy. In other cases where the sample concentration is higher, then multi-point calibrations are nearly always recommended. It’s important to use calibration standards around the range of analysis, so if your samples are 80-100ppm then we would suggest a set of calibration standards at 70, 80, 90, 100 & 100 ppm.
How do I choose whether single point or multi point calibrations are best for my application?
Yes, but be caution of cross contamination, and variances and tolerances in pipettes. Good lab Practice should be employed at all times.
In order to help ensure precise sampling, can we use a transfer pipette?
A de-proteinising solution is any cleaning agent that works well cleaning off proteins. Decon 90 is one of these types of cleaning agents that we provide. Proteins in samples can clog the capillary tube of the nebuliser and, with extended use, form a coating in the mixing chamber and burner tube where they can affect the results. Regular cleaning should form part of a maintenance schedule, more of which is discussed in the operator manual.
What is a de-proteinising solution?
The burning of a propane flame is not harmful, however, your samples may well be. It is down to each laboratory to conduct their own risk assessment based on the contents of samples to determine whether a fume cupboard is required. If used then it is important that the draw of air flow does not have an impact on the stability of the flame.
Do I have to run the instrument in a fume cupboard?
Our operator manual gives a clearly defined maintenance schedule and instructions for the cleaning of each component but if you need some advice prior to purchasing then please get in touch <link> and we’ll be more than happy to help.
How do I clean a flame photometer?
This varies per application and per laboratory, some samples will be particularly aggressive or contain large salt content and so more regular cleaning may be required. Our operator manual gives a clearly defined minimum maintenance schedule and instructions for the cleaning of each component but is down to the standard operation procedures of each laboratory to determine if this is satisfactory based on the application. We can of course support with advice and guidance where required, just get in touch.
How regularly must I carry out cleaning or maintenance?
You cannot, it is of vital importance that you make no attempt to adjust the nebuliser from the factory supplied setting. Adjustment of the nebuliser invalidates the warranty for the component and will prevent you from achieving results meeting our published specification.