摘要:

The mercury vapor monitor, MDC-1-01, described in this paper is the first prototype in the MDC series. It was designed and developed in our laboratory to measure airborne mercury vapor on a “continuous” basis in the range of 400 ng to 20 mg mercury per cubic meter of air.

ISSN:1073-9149    

DOI:10.1080/10739147308543373

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A system is described for optimizing the input-output electronic circuit parameters of photometric detectors. It is oriented directly to their use as mercury detectors in air pollution monitoring. Detailed procedures are given whereby the electronic power circuits can be permanently stabilized. In addition, a new input design is presented that eliminates the need for log-ratio concentration outputs in these devices. A direct application of such circuits is presented with actual results.

ISSN:1073-9149    

DOI:10.1080/10739147308543374

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Fabrication of a new pressure jump cell made entirely from Plexiglas is described. Chemical relaxation effects greater than 50 μsec can be measured when the pressure on a chemical system is suddenly released from 40 atm by means of a bursting phosphor-bronze diaphragm and the resulting conductance change is measured by a Wheatstone bridge arrangement.

ISSN:1073-9149    

DOI:10.1080/10739147308543375

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A new design for a pulse polarograph suited for both manual and remote operation is described. The use of integrated circuit techniques and the two-drop operation allow for an output effectively free of noise and background, and without peak distortion. The sensitivity limit is below 1 ppb.

ISSN:1073-9149    

DOI:10.1080/10739147308543376

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Relatively inexpensive and simple modifications to an AEI MS-902 double focusing high-resolution mass spectrometer allow chemical ionization studies to be undertaken without compromising the instrument's high resolving power or sensitivity. A standard AEI source block was made gas tight except for a 0.013 to 0.020 in. diameter ion exit and an 0.013-in. electron entrance hole. A specially designed direct insertion probe was utilized to introduce both the sample and reagent gas. The reagent gas itself was supplied via a system utilizing both the manufacturers cold inlet system and Matheson lecture bottles. An additional pumping system was added in parallel to the existing pumping system to handle the increased gas flow.

ISSN:1073-9149    

DOI:10.1080/10739147308543377

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

An inexpensive (∼ $120), versatile, easily constructed digital integrator is described. Linearity is better than 1% for voltages of 0.1 to 15 V inputs. Input uncertainties are ≤ ∼ 200 μ V. Input impedance is ∼ 0.5 M. Integrals spanning at least a 1000:1 range can be read with 1% or better accuracy without varying the gain. Sensitivity is 5 count/V-sec, but higher or lower sensitivities are available by changing component values. A memory permits the integral at a particular instant to be locked into the display without any effect on the continuing integration. The reset, store, and track controls are transistor transistor logic compatible and may be operated by external circuitry for added versatility.

ISSN:1073-9149    

DOI:10.1080/10739147308543378

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147308543379

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147308543372

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor