Deployment Devices

SPMDs have been snccessfully deployed in a variety of deployment devices (Ellis et al., 1995 Lebo et al., 1995 Petty et al., 1995). The commercially available 

Because SPMDs sequester a wide variety of organic solutes or vapors of hydrophobic chemicals, care must be used to prevent inadvertent contamination of the devices. Of particular concern for SPMDs destined to be used for environmental sampling is the fact that SPMDs clear large volumes of vapor phase chemicals from air. For example, under low flow conditions ( 5 cm s ) at about 22 °C the Rs 

The procedures given above are designed to prevent any contamination of SPMDs, to minimize losses of PRCs and accumulated analytes, and to reduce the possibility of analyte photolysis. These precautionary steps are particularly important when target compounds are at ultra-trace levels, as it may be difficult to delineate handling, storage and shipping-related contamination from analytes concentrated during the exposure. 

Successful applications of the SPMD technology under a wide variety of field conditions have been demonstrated by a number of researchers (see Appendix B or CERC, 2004). The common threads among successful applications of SPMDs are a basic understanding of potential sources of sample contamination and losses, the functional aspects of the SPMD technique, and the adherence to sound sampling approaches and good laboratory practices. 

Bartkow, M.E. Huckins, J.N. Muller, J.F. 2004, Field-based evaluation of semipenneable membrane devices (SPMDs) as passive air samplers of polyaromatic hydrocarbons (PAHs). Atmos. Emiron. 38 5983-5900. 

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Physically, the MIMOS II Mossbauer spectrometer has two components that are joined by an interconnect cable the sensor head (SH) and electronics printed-circuit board (PCB). On MER, the SH is located at the end of the Instrument Deployment Device (IDD) and the electronics board is located in an electronics box inside the rover body. On Mars-Express Beagle-2, a European Space Agency (ESA) mission in 2003, the SH was mounted also on a robotic arm integrated to the Position... 

Fig. 8.30 The Instrument Deployment Device (IDD) above the surface of Mars, showing all the four in situ instruments left) the MIMOS II with its contact ring can be seen in the front picture taken at Meridiani Planum, Mars right) MIMOS II is located on the left side picture taken at Gusev Crater, Mars...

Decreasing power demand increasing density of deployment Device to sample... 

Autonomous (long-term ) Ttefd Deployable Devices ... 

Sampling rates for the case of total boundary layer-control can be expected to be nearly independent of temperature, since both the diffusion coefficients in air, and the kinematic viscosity of air are only weak functions of temperature (Shoeib and Harner, 2002). This leaves the air-flow velocity as the major factor that can be responsible for the seasonal differences among sampling rates observed by Ockenden et al. (1998). The absence of large R differences between indoor and outdoor exposures may be indicative of membrane-control, but it may also reflect the efficient damping of high flow velocities by the deployment devices used for SPMD air exposures (Ockenden et al., 2001). 

Figure 4.1 A stainless steel deployment device designed by Harrry Prest, Santa Cruz, CA, which has the capacity for four 1 ml triolein SPMDs. The whole apparatus, loaded with SPMDs, fits in a 3.85 L gas tight steel can (Figure 4.2) for transport to and from the field.

Huckins, J.N. 1998, Effect of deployment devices on performance reference compounds (PRCs) loss. USGS Columbia Environmental Research Center Columbia, MO Unpublished work. 

The crucial missing part in this scenario is the gateway through which these worlds will communicate how can the digital world sense and respond to changes in the real world Unfortunately, it would appear from the lack of field deployable devices in commercial production that attempts to integrate molecular sensor science into portable devices have failed to bear the fruits promised this problem is what we call the chemo-/biosensing paradox.4... 

Figure 12.16 Alpha particle X-ray spectrometer (APXS). To determine the elemental composition of rocks and soils of Martian surface, the rovers, which landed in 2004 on Mars, carry a deployment device that could be in contact with the rocks. The sensor head contains six Cm radioactive sources, six alpha detectors and one X-ray detector in the centre. The accumulation time is a few hours per sample analysed.

The Mission Module is mission specific and includes all science instruments and supporting equipment necessary to meet science requirements. The supporting equipment may have included the following scan platform, turntable, associated electronics, booms, deployment devices, radiation shields, cabling, muiti-layer Insulation and thermal control devices, and flight software. 

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