Warm-up time

Where these valves are used, the time available to warm up the pipe work will be known, as it is set on the valve control. In other cases, details of the start-up procedure must be known so that the time may be estimated. Thus boilers started from cold may be fired for a short time, shut off for a period while temperatures equalize, and then fired again. Boilers may be protected from undue stress by these short bursts of firing, which extend the warm-up time and reduce the rate at which the condensate in the mains must be discharged at the traps. 

Such fluids often referred to as 5/95 fluid (that being the ratio of oil to water), have essentially the same properties as water with the exception of the corrosion characteristics and the boundary lubrication properties, which are improved by the oil and other additives. The advantages of this type of fluid are fire resistance, lower fluid cost, no warm-up time, lower power consumption and operating temperatures, reduced spoilage of coolant, less dependence on oil together with reduced transport, storage, handling and disposal costs, and environmental benefits. 

The required warm-up time will vary with ambient conditions, being longer in cold weather and least in warm. Optimum-start controllers are now in general use which are programmed for the building warm-up characteristics and sense the inside and ambient conditions. They then transduce the required start-up period and set the heating plant going only when needed. This, and the previous scheme, will save fuel. 

For solution nebulization MC-ICPMS and MC-TIMS, typical runs consist of up to 100 ratios collected over 30 minutes to 1 hour. This includes time for background measurement (typically monitored at half mass on either side of the peak) and peak centering, but excludes filament warm-up time for TIMS and nebulizer cleaning for MC-ICPMS. Sample sizes of-1000-10 ng of total U for TIMS and MC-ICPMS are required to attain 2a measurement uncertainties of a permil or better on (e.g., Stirling et... 

Irganox 1010 could be extracted from PP in 18min, using propan-2-ol-cyclohexane (97.5 2.5). For plasticiser extraction from PVC, optimum conditions were hexane-ethyl acetate (60 40) at 170 °C, giving effectively complete extractions after 13 min. For nylon, the optimum conditions were hexane-ethanol (60 40) at 170 °C, and extractions from ground material were 95 % complete after 16 min, including warm-up time. Irganox 1330 was used as an internal standard in PP, n -C1() in... 

Switch on the microwave bridge to tune mode (and allow two minutes warm-up time). 

Sometimes, to get data from 4 K up to room temperature, the simplest and more economical way is to let the cryostat warm if the thermal insulation is good and the vacuum chamber is kept under pumping, the warm-up time can be several days. If the experiment thermal time constant is much shorter, data at practically constant temperature can be recorded. 

PEM fuel cells operate at relatively low temperatures, around 80°C. Low temperature operation allows them to start quickly (less warm-up time) and results in less wear on system components, resulting in better durability. However, they require that a noble-metal catalyst (typically platinum) be used to separate the hydrogen s electrons and protons, adding to system cost. The platinum catalyst is also extremely sensitive to CO poisoning, making it necessary to employ an additional reactor to reduce CO in the fuel gas if the hydrogen is derived from an alcohol or hydrocarbon fuel. This also adds cost. Developers are currently exploring platinum/ruthenium catalysts that are more resistant to CO. 

NMR instruments often require a considerable warm-up time and are frequently left on constantly to ensure consistent performance. They should be situated on a low-vibration surface and kept close to room temperature. Regular calibration is essential for the success of the direct method. It is good practice to keep a day-to-day record of the F factor of the instrument and use sudden changes as an indication of a problem. 

Treatment Go have another cup of coffee before shooting another sample. If warm-up time becomes excessive, consider replacing the lamp or calling a serviceperson. 

Figure 7 The effect of inadequate burner head warm up time on the absorbance (top) and emission (bottom) signals from repeated nebulization of a 10 mg l 1 aluminium solution...

Optimization in Flame AAS Source-related Parameters Effect of Lamp Current Effect of Lamp Warm Up Time Lamp Alignment Lamp Deterioration Choice of Lamp Atomizer-related Parameters Choice of Atomizer Effect of Fuel-to-oxidant Ratio Optimization of Burner Position Burner Design, Warm Up, and Cleanliness Gas Flow Stability Monochromator-related Parameters Choice of Slit Width Choice of Wavelength Optimization in Flame AFS Source-related Parameters Lamp Operating Parameters Lamp Alignment Atomizer-related Parameters Monochromator-related Parameters Optimization in Flame AES... 

The recommended conditions for determining the elements by AES and AAS spectrometry are given in Table 1. After a suitable burner warm-up time, one AES or AAS reading is obtained on each calibration standard and sample solution using an 8 to 10-second integration time. The process is repeated at least two or three more times to acquire an average of three or four readings for each solution. 

Zero warm-up time for efficient intermittent operation ... 

Phosphoric acid fuel cells (PAFCs) utilize liquid phosphoric acid as the electrolyte. These types of cells can achieve efficiencies up to 80%. They are usually large and heavy and require warm-up time. 

Medium- or large-sized reformers can be installed at fuel cell vehicle-fueling stations. At these scales, the equipment complexity, warm-up time, and transient response are not issues pollutants can be controlled more effectively and existing power infrastructures can be used. The facility must store only small amounts of hydrogen and hydrogen transportation is avoided. 

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