By observing aerobe processes by means of gas analysis a direct deduction can be made on the condition of the cultivation.
Thus, for instance, oxygen or substrate limitation can be recognised immediately. On the basis of the gas analysis growth rates [µ] can also be calculated.

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A gas analysis is excellently suited to regulate bioprocesses as this analysis method is very resistant to failure. By using BlueSens sensors precise measurement values can be analysed directly in the exhaust line. Thereby parameters such as e.g. the oxygen uptake rate (OUR or OTR), carbon dioxide production rate (CER or CTR) and the resulting respiration quotient (RQ) can be calculated. Then, to prevent oxygen limitations, the gassing rate and the rotation speed of the fermenter agitator can be adjusted. By the well-directed substrate feed (based on the RQ) unwanted effects (e.g. Crabtree) can be prevented. 

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Carbon dioxide (CO2), oxygen (O2), methane (CH4), hydrogen (H2), ethanol (EtOH), methanol (MeOH) and carbon monoxide (CO).

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a) infrared for CO2, CH4, EtOH, MeOH and CO
b) zirconium dioxide-probes, resp. electro-chemical for O2
c) thermal conductivity for H2

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a) the individual sensors can be implemented more flexibly
b) BlueSens sensors can be integrated directly in pipes (exhaust gas line) and do not require gas treatment (e.g. cooling)
c) the cost/performance of our sensors is excellent

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The idea of gas multiplexing is based on the fact that gas analysers are expensive, that measuring gas has to be dried and by no means may particles enter the analyser. The BlueSens sensors have been especially developed for processes with high water contents and pollution burden.
a) no exhaust gas cooler required
b) avoidance of long gas feed lines
c) no complex valve circuits required
d) additional software for the control of the valves and measured data collection superfluous
e) measurement conform with PAT
f) Regulation by large amount of available data possible

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Any measuring device has to be calibrated and serviced to ensure perfect operability. BlueSens sensors only suffer a minimal drift. This can be further minimized by a 1-point-calibration once a month. To improve precision at the operating point each customer can carry out a 2 point adjustment with our diagnosis software (BACCheck) and the suitable test gas himself at site. Principally, however, a 2 point calibration is not necessary.

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The life expectancy depends on the measuring principle. 
a) based on their principle infrared sensors last for 2-3 years
b) in the case of electro-chemical sensors life expectancy for the O2 sensors is 900,000Vol%h
c) Zirconium dioxide-sensors last, based on their principle, for approx. 15,000 operating hours

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We generally recommend annual maintenance for the sensors to ensure perfect operability. Here we offer the package Blue4Care incl. extension of guarantee by one year. In the scope of this package we replace all the necessary elements and recalibrate the sensors. Of course merely repairs may be carried out as required. The costs for the latter depend on the amount of work involved. The respective costs depend on the job to be completed and can be found out by applying for a cost estimate.

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As a rule one week. Should maintenance, repairs respectively, take longer than expected, units can be hired and placed at disposal for this period.

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BlueSens sensors measure non-stop and every customer can decide at which measuring intervals he would like to get the measured values.

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The transfer can be effected by means of a 

a) power signal 4-20mA 

b) serial data transfer RS232

c) Ethernet TCP/IP

d) USB

e) RS485

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On principle BlueSens sensors may not be installed and used in explosive gas mixtures or zones endangered by explosion as the sensors do not have an ATEX certificate.
Example for exceptions: CH4 sensors may, of course, be installed in biogas plants - where, as a rule, no ignitable gas mixture is available.

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The sensors are, thanks to their innovative design, not dependent on flow rate. Generally attention must be paid to what pressure ratios are available in the line.

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Yes, as is the case for most sensors the BlueSens sensors, based on principle, depend on pressure. BlueSens sensors are, however, always supplied with pressure compensation. To ensure that the latter is correctly implemented all the pressure ratios of your application are queried already in the bidding phase. 

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BlueSens sensors have temperature compensation in the given temperature range and thus reveal no dependence on temperature.

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As BlueSens sensors are heated and regulated at a certain temperature the measured value may diverge when used beyond the given temperature range.

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Principally no, as the sensors are heated to prevent such condensation within the sensor. Please note the data sheet for the storage of each sensor.

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Our sensors are calibrated to dry test gases, in the case of humid gases they indicate less than for dry gas.
We define the latter as dilution effect which is only influenced via temperature. There are tables in our operating manuals from which the dilution effect - factor for compensation can be found.

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The decisive point for comparative measurements is

a) what is the comparison made with, dry gases or humid gases

b) is the comparative device fitted with pressure compensation
c) and is the comparative device fitted with temperature compensation?

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No, BlueSens sensors have only been conceived for the gas phase.

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That should principally be avoided. However, the sensors are protected by hydrophobic filters against fluids on the short run.

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The filters have to be checked at regular intervals. There are no general guidelines for replacement as the latter depends on the application. Examples:

a) they have to be replaced when foam penetrates the line or there is other pollution in the line
b) if the measuring signal is slower than it was originally

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Yes, all sensors are fitted with the appertaining tools. (Article No.: F-PTFE-13-050-1)

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CO2: none
CH4: all hydrocarbons
EtOH: all hydrocarbons
Methanol: all hydrocarbons
CO: to CO2
O2: none
O2-ec: none
H2: all gases

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We gladly submit an offer without engagement.

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BlueSens sensors can be connected to all types and sizes of fermenters mechanically. Either directly via Tri-Clamp(SMS 38), 1 1/4" connectors or in the case of smaller fermenters by flow adapters. All we need here is the inside diameters for soft tubes or the outside diameter for hard tubes or metal pipes.

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Principally the degree of efficiency can be calculated. The BlueSens sensors come up with a reliable methane value as they can be installed directly in the line near the CHP.

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