Instrumentation field checks

Low flash-zone temperature. Have the instrument mechanic check the furnace outlet thermocouple. The optimum tower top temperature for a vacuum tower equipped with a precondenser is usually not the minimum temjjerature. As the tower top temperature is raised, heavy naphtha boiling-range materials are flashed overhead into the precondenser. Acting as an absorption oil, they absorb a portion of the light hydrocarbons that would otherwise overload the jets. However, getting the vacuum tower top too hot can overload the precondensers. By field trials, find the tower top temperature (usually 230°F to 280°F), that minimizes flash-zone pressure. 

Liquid level above seal pan in bottom of column. Poor stripping of bottoms product. High pressure drop across section. Board mounted instrument improperly calibrated. Level gauge in field not properly blown down or even checked. Operation problem. 

The operational test of the lube system is, as the name implies, a functional test to check as many of the features as practical under running conditions. The first and last step is a demonstration of the cleanliness of the system. This is followed by a running test of a four-hour duration. The test should simulate the field operation with the compressor in every way practical. All equipment to be furnished with the lube system should be used in the test, including the standby pump start and trip switches. All other instruments should be used to demonstrate their operation. Prior to starting the four-hour run, the system should be thoroughly inspected for leaks and the leaks corrected. If no steam is available for a steam turbine (if one is used), the four-hour run can be made on the electric pump. However, every effort should be made to use an alternate source of energy such as compressed air, to operate the steam turbine. 

A typical field test involves several steps (a) transporting the mobile unit to the site (b) instrument warmup (c) system check out, consisting of mobile unit measurements of distilled water and a 1-ppm stock phenol solution and (d) in situ measurements of the well water, repeated three times for statistical analysis. Signal levels recorded at a field site may be reported as equivalents of phenol (or other calibrant) using the calibration curves. Therefore, this method allows us to report the upper bounds of pollution levels. 

There may also be a need for standards that can be used to calibrate instruments, check for progressive shifts in their measurement responses, and ensure that data acquired from different sources are comparable. In most other analytical fields we have standard materials, and these should not be hard to establish. Amongst those that we use is a homogeneous pyrophyllite from the Manuels deposit near St. John s. 

Normal operation—The computer system is maintained in accordance with the planned preventative maintenance schedule. Typical activities include recalibrating field instrumentation and computer I/O cards in accordance with site calibration procedures, running system diagnostics, checking operator logs for any abnormalities, and planning service visits by the system supplier. 

Organize Analytical Batches—These include analytical QC checks (instrument blanks and other QC checks as required by the method), CCV standards, prepared field samples, and laboratory QC samples. 

To check the temperature rise in the liquid sample under high fields, we have tried two preliminary approaches. First, we used a radiometer designed in our Instrument Development Laboratory. 

This is a check of all the standard panel alarm lights and a review of any work that remains to be accomplished. (This panel alarm light audit is not for the new technology of distributed control instrumentation.) As a cross-check, a review of all the out-of-service tags of the previous week will be made. Each of the safety shutdown system valves that have been bypassed during the previous week will be inspected in the field to ensure that they are neither blocked nor operating with the bypass open. 

Field measurement instruments should be checked for their limits of detection, accuracy, and reproducibility, and their measurement errors should be established. This can be done with standards, duplicate samples, and dilution of samples, similar to the checks discussed for laboratory measurements (section 5.9). Such checks should be performed in preparation for field work, and the results should be recorded and reported with the... 

The operation of instrumentation must be checked from the field to the control room graphics display unit or local controller I/O registers as applicable, depending on the type of system installed, and vice versa. The operation of control instrumentation (e.g., control valves, actuated on/off valves) should be checked by energizing each control system field output from either the control room display or local controller as applicable, and observing and recording the results. 

The operation of monitoring instrumentation (e.g., transmitters, switches) should be checked by either injecting a suitable signal at the field instrument terminals or by installing the instrument in a comparator (e.g., a hot oil bath, dead weight tester). The result received by the control system on the control room display or local controller I/O register, as applicable, should be recorded. Any problems should be reported to the company/companies responsible. 

Field Instrument Installation - Installation and Check-Out - ( 0.3 of Material )... 

Undoubtedly, this new kind of integrated approach is well representative of what should be membrane engineering, with final objectives clearly defined, the right hypothesis and choice of simple equations for modeling, a realistic representation of real complex solutions and the set-up of efficient simulation tools involving successive intra- and extrapolation steps. It appears to be easily extended to other membrane operations, in other fields of applications. It should provide stakeholders with information needed to make their decision costs, safety, product quality, environment impact, and so on of new process. Coupled with the need to check the robustness of the new plant and the quality of final output, it should constitute the right way to develop the use of membranes as essential instruments for process intensification with industrial units at work. 

Consideration of the analyses performed on the 8-channel and both models of the 12-channel Technicon equipment in relation to the earlier discussion means that these latest developments in the field of Auto-Analyzer instrumentation demand standardized sera for calibration purposes. In fact, the successful operation of the SMA-12 instrument is entirely dependent upon the careful analysis and subsequent stability of the standardizing serum, since this is used both for the initial calibration of the various analytical channels and for the subsequent monitoring for drift and application of any correction needed as a result of instrumental drift. Apart from this large demand for standardizing serum (about 70 ml in an 8-hour day), the performance of the SMA-12 should in addition be checked by means of control sera, as for any other method or combination of methods in clinical chemistry. The expense of the standardizing (and to a lesser extent the control) sera used in SMA-12 operation constitutes an important but nevertheless essential fraction of the operating costs of these instruments. 

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