Temperature Controller Board

The Mass Spectrometer Module houses the vacuum system, capillary interface assembly, and ion-trap mass spectrometer in approximately half of the module. Also included are the reagent gas and calibration gas subassembly (a temperature-controlled housing that ensures consistent gas pressures). The other half contains the electronic printed circuit boards, power supplies, and instrument control computer. 

A hairdryer and a can of HFC-134a ( Freon ) can help do quick temperature testing. But if you decide to put the board in a temperature-controlled oven, you should be aware that normal scope probes can melt or warp under extremes. Also choose your cables carefully (try Teflon-coated ones). Teflon cables can be very brittle, however. 

Oleum is marketed in a range of strengths up to c. 65 per cent S03. From 0 to 30 per cent free S03, it is a liquid from 30 to 55 per cent free S03 it is a solid (maximum m.p. 35 °C at 45% free S03) from 60 to 70 per cent free S03, it is a liquid. The acid must be kept in ground glass stoppered thick-walled bottles. If it is required to melt the acid, the stopper is removed, a watch glass placed on the mouth of the bottle, and the bottle is placed on a uralite board in a warm temperature-controlled oven at 40 °C. The liquid should be removed from the bottle with the aid of an automatic dispenser fitted into the neck this procedure is more satisfactory than that of pouring the liquid acid from the bottle. 

For large installations several hundred couples may be connected to a switchboard and the operator of the board connects the couples successively to the indicator. The switchboard is frequently designed somewhat similar to an ordinary telephone distributing board. Often in these large installations communication between the operator of the switchboard and the operator of the furnace is maintained by a system of colored electric lamps. This method of semi-automatic temperature control is meeting with great success in the industries. 

Figure 3.28. Schematic of laser-induced cold-wall CVD reactor [57] (1 C02 laser, 2 reflector, 3 laser beam, 4 GaAs lens, 5 cooling water, 6 reactor, 7 nozzle, 8 reaction flame, 9 particle plume, 10 board, 11 window, 12 throttling valve, 13 powder collector, 14 pump, 15 pressure gauge, 16 water-cooled Cu block, 17 temperature controller, 18 oven, 19 heater, 20 precursor vessel, 21 liquid HMDS, 22 needle valve, 23 flow meter, 24 preheating tube, 25 co-axial protection gas, 26 lens protective gas)...

The temperature of the furnace is continuously varied by a temperature controller, and the outputs from the balance and from the sample temperature thermocouple are logged by a computer fitted with a 16-bit dynamic range data acquisition board. The signals are processed via a program derived using a combination of Virtual Basic and C++ and the derivative of the TGA curve is used to control the heating program via the temperature controller. 

The G.P. chamber is equipped with an air cooler of about 5500 BTU size (Item 3) is located about 1.8 meters off the floor. An evaporator control valve (Item 2) on the refrigerate line allows temperature control of the air cooler condenser coils. Temperature of the coils is maintained just above the dew point for 50% relative humidity. An electric baseboard heater (Item 6) is equipped with a hydrastatic thermostat control (Item 11). The base board heater is placed near the floor and opposite of the chamber door. A humidifier (Item 4) is located approximately 1.8 meters above the floor and just to the right of the air cooler. The nozzle of the humidifier is pointed slightly toward the back of the chamber. A humidistat (Item 10) is centered between the floor and end walls on the same side as the humidifier. A strategically located recording hygrothermograph is used to monitor both temperature and humidity. 

The control strategies are programmed in Matlab-Simulink, compiled in C-H-and then downloaded into the DSP processor of the d-Space board. The controlled management of the fuel cell system during the dynamic tests operates on hydrogen purge, air flow rate regulation (stoichiometric ratio), external humidification, and stack temperature. 

The device was manufactured as two parts the first part is a disposable silicon chip - with the electrochemical cells arrays. The sihcon chip was wire bonded to a special printed circuit board (PCB) platform, which was directly connected to the data processing units. The second part of the device is reusable, which includes a multiplexer, potentiostat, temperature control and a pocket PC for sensing and data analysis (for more details see [5]). This design enables performance of multi experiments simultaneously and each electrochemical cell can be measured independently. The total weight of the entire system is -900 g, making it ideal for medical applications. 

The heart of the system is a microreactor packaging scheme that is based upon a commercially available microchip socket. This approach allows the silicon-based reactor die, which contains dual parallel reaction channels with more than 100 electrical contacts, to be installed and removed in a straightforward fashion without removing any fluidic and electronic connections. Various supporting microreactor functions, such as gas feed flow control, gas feed mixing, and various temperature control systems, are mounted on standard CompactPCI electronic boards. The boards are subsequently installed in a commercially available computer chassis. Electrical connections between the boards are achieved through a standard backplane and custom-built input-output PC boards. A National Instruments embedded real-time processor is used to provide closed-loop process control and... 

The temperature controller board (Fig. 12.10) consists of five CAL (CAL Control Inc., 1580 S.Milwaukee Ave., libertyville, IL 60048) 3300 temperature controllers mounted on a standard 6U CompactPCl boards. These devices are used to control the temperature of the DieMate manifolds and the product transfer lines by manipulating the power input to their respective heaters. Two controllers are... 

Integration of various components is an important issue for the DCF systems. The simple scale-up of microreactors is not enough as the DCF system. A DCF system should consist of not only reactors but also other factory parts like a mixer, separator, and temperature controller. Many integrated microreaction systems have been reported and some of these are commercially available. For example, K. F. Jensen s group has reported an integrated microreactor system for gas-phase catalytic reactions using microstructured reactors and other devices on a computer board [13]. They have achieved computer control over the reaction system through this device as shown in Fig. 6. 

An internal power supply module provides the power needed by certain components within a fuel cell system. The components include sensors, control boards, pumps, fans, blowers, compressors, solenoid valves, contactors, switches, and so on. The IPM also provides the power to start the fuel cell system and helps carry some load when the fuel cell stack is inadequate to handle a sudden load jump. There are many types of sensors in a fuel cell system, such as the H2 concentration sensors, the H2 pressure sensors, the fluid flow rate sensors, the coolant-level sensors, the temperature sensors, the current sensors, the voltage sensors, the door-open sensors, the vibration sensors, and the flooding sensors. These sensors monitor the corresponding parameters to indicate the situation of the entire fuel cell system. The control boards may include a main board for controlling the system and several sub-boards for controlling various modules discussed in this chapter. Pumps, fans, blowers, compressors, solenoid valves, contactors, and switches all require power to perform the corresponding functions. 

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