Frequently asked questions

DELIVERY TIME

• What is the lead time of Powder Doser?
  We have DOSERs in stock and it can be delivered to you within a few days from order. Practically, it is only the time taken for shipping

CREDIT CARD PAYMENT

• Do you accept Credit Card payments?
  You can pay using your credit card via PayPal. Most importantly, it is not necessary to have a PayPal account to make the payment via credit card.

POWDER TYPE

• Could you please confirm the particle size that can be fed by the dosing system? Can the powder doser handle powders at 20 microns or ~500 mesh?
  The biggest particle size for powders that could be dosed with our DOSER is about 4 mm. A good dosing of powders depends essentially on the flowing properties of the respective powders to be dosed. In general, homogeneous and free-flowing powders can be dosed best.
• How does the LAMBDA DOSER work with the substances which are prone to agglomeration?
  The powder / granules / solid must be properly treated for good flowing properties It is also possible to allow a gas flow to pass through the Lambda dosing vessel in order to create a controlled atmosphere.
  It is often possible to substantially improve the flowing properties of the respective powder / granules / solid by adding Aerosil (fumed silica – pure SiO2) to your powder (~0.1 - 2% by weight).
• Is it possible to dose our fibrous, needle shaped and hygroscopic (ground, dry sugarcane bagasse and miscanthus) materials?
  DOSER is airtight which is useful during work with oxygen sensitive or hygroscopic substances. It is possible to introduce a gas flow (e.g. N₂, Ar, etc) by a special gassing plug (art. 5808-g: unit price=10 EUR).
• How the LAMBDA DOSER reacts to abrasive powders? Will the components get damaged over time with continuous abrasion?
  In the case of abrasive materials being used with the LAMBDA Powder DOSER, you will have an opportunity to replace the glass vessel and / or the distributors as needed.

DOSER FOOTPRINT

• What are the dimensions and footprint of the entire DOSER apparatus?
  Dimension of the DOSER is: Motor unit: 6 (H) x 7 (W) x 13 (D) cm Glass vessel approx. 0.2 l: 30 (H) x12 (W) x 5 (D) cm Glass vessel approx. 1 l: 30 (H) x 18 (W) x 14 (D) cm (which could be found in our leaflets and website at

ACCURACY

• What is the accuracy of the each dispensing?
  The motor of the driving unit is controlled with quartz-driven electronics, similarly as it is done in electronic watches.Therefore, the accuracy depends mainly on the powder. For best accuracy and precise doses, the powder needs to be free-flowing and homogenous.

FOOT SWITCH

• Can the foot switch be an on/off toggle?
  It is possible to have an ON/OFF toggle switch. But, we need to customize it for you and it will take some time.
• Is there a way to configure the foot pedal to activate the Run button so that a single cycle of the program is performed?
  The foot switch can be customized to execute the flow rate program using the foot switch.

FLOW RATE

• Can the Lambda DOSER control the mass flow rate (g/min) of the powder being dispensed?
  It is always possible to control the mass flow rate of the powder using the LAMBDA Doser. You could program the DOSER up to 27 pairs of speed and time settings to control your desired mass flow rate (g/min).
• Can the LAMBDA DOSER (powder doser) also dose intermittent (meaning, with a pause between each dose) or can it only dose a continuous stream of powder?
  Yes, the DOSER can also dose with pauses in-between each dose.
  • You can simply set the speed = 0 (zero). It can be done directly on the DOSER while programming the profile.
  • You can also remote control the DOSER by on/off signal.
• Can I use this equipment to control the feed rate of powder?
  Yes, the feed rate of the powder could be controlled using LAMBDA DOSER. The dosing rates of the powder DOSER and HI-DOSER can be selected over a large range, e.g. for NaCl the dosing rates can be varied from 50 mg/min to 50 g/min with DOSER and 250 mg/min to 250 g/min with HI-DOSER.

DOSER VESSELS

• Is the 0.2L feeder section interchangeable with the 1L vessel?
  Doser vessels are interchangeable. It is possible to use the same control unit (Art. No: 5809) with both the 0.2 and 1L vessels.
• Do you have these vessels for LAMBDA powder DOSER in any other material than glass? We are interested in clear plastic vessels if you were to have them.
  LAMBDA does not produce plastic vessels for Dosers or fermentors. If you are afraid of glass vessels being broken, then it could be prevented when the external surface is plasticized by the silicon layer.
  The silicon layer is about 0.2 mm thick and almost transparent. In case of breakage, all pieces are held together.
  On the other hand, the elastic layer considerably protects the glass from scratches and breakages are much less probable because shocks are much milder.
• Are the vessels exchangeable? We would like to buy a spare glass container for our powder doser.
  Yes, in most cases the vessels 0.2L and 1L for the LAMBDA Powder DOSER are simply exchangeable. You might have to send the serial number and/or invoice number of your DOSER to LAMBDA for verification and a new quotation.

PARTS OF DOSER UNIT

• Could you please explain the difference between the "Distributor (normal)" Model 5804 and the "Distributor for very fluid powders" Model 5805?
  We usually supply the 'normal' distributor. The 'fluid' distributor is recommended for highly flowing powders where the distribution is minimized and therefore has a much lower maximum flow rate (~5 g/min) which depends on the specific weight of the powder.
• What are the materials of the Doser parts?
  The storage vessel is made of borosilicate glass (optional with outer silicon coating). The screwing connection is made of autoclavable Phenol Plastic. The rotating distributor is made also from highly resistant epoxide and PTFE. Further materials are epoxy resin and Teflon.
• What is the 5808-g gassing plug for?
  Gassing plug is used to introduce / purge the glass vessel with the desired gas flow (e.g. N₂, Ar, etc), in-case of dispensing oxygen sensitive or hygroscopic substances.
• Is there any part of the system kind of “pushing” the powder out to be supplied?
  The motor of the driving unit is controlled with quartz-driven electronics, similarly as it is done in electronic watches. The powder distributor is of an open spiral type (not a screw type as is sometimes used in other systems and can lead to the compacting and blocking of the dosing screw). This spiral takes the powder and pushes it to the centre where it falls out of the dosing unit.
  Please watch the video of the powder dosing system at our video channel for better understanding.

SAFETY

• Can you please also confirm if the system would be supplied according to our standard electrical connection?
  The Doser is powered by 12 V/ 6 W DC switching power supply. All power supplies used have attested for local nets and sockets. From the net socket you work only with 12 V DC, which is perfectly a safe voltage.
  Alternatively, the DOSER can also work with 12V car battery.
• Is the powder doser intrinsically safe?
  Although the LAMBDA DOSER powder dosing system operates at low voltage (12V DC) and with low power (< 6W), however, the instrument has not been certified explosion proof.
  The LAMBDA DOSER can be purged e.g. by a protective gas (N2, Ar,..) and we can provide also silicone coated glass vessels, if desired. Alternatively, the instrument could also be placed e.g. in a box with an inert atmosphere with a slight overpressure.

TEMPERATURE RESISTANCE

• How high can the temperature be without this parts melting or getting damaged?
  The black closing part (not the electronics) should withstand the sterilization temperature which is about 120 to 130°C

PC CONTROL

• Could you provide me information about relevant connections/interfaces to provide PC control via USB?
  We offer RS-485 or RS-232 interface along with the communication cable for PC control. It is possible to control the DOSER with PNet PC control software.
• Can you clarify the differences between the 485 and 232 interfaces?
  RS-485 is definitely recommended for the control of several instruments from one computer, because it allows communication with up to 99 instruments from one single port (COM port). But with RS-232, you would be able to connect only one instrument. The communication protocol stays the same and the connection is similar to RS-232. Could not find the information that you are looking for? Please contact at support@lambda-instruments.com for any further questions.

INTEGRATING DOSER WITH METTLER ACCESSORIES

• Is it possible to control the DOSER via Mettler Toledo titroprocessor, T50/T70 to dispense NaF to the titration process when required?
  Yes, the powder DOSER can be controlled by Mettler Titration Excellence T50/T70/T90 via RS-232 communication (most common type of connection with Mettler accessories), to dispense the desired amount of powder to the titration process.
  The powder DOSER has to be included as RS-232 control in the titroprocessor unit and the desired activity can be selected (e.g.: the signal would switch off the DOSER or switch it on, etc.)
  For integration of DOSER with your Mettler titroprocessor, you would need the RS-232 interface activated in the powder dosing unit and RS-232 connection cable.