Monitoring process parameters

A development of the moving die rheometer where the operation of the unit is fully computer controlled. The rate of oscillation, temperature and level of strain can all be run through a series of options. The torque measurements are also highly sophisticated. As a consequence, the unit can be set up to monitor processing parameters, then the cure behaviour and finally the finished dynamic properties of the cured material. It is manufactured by Alpha Technologies. 

Continuously monitoring process parameters, stack emissions and ambient air quality. 

Process Control Equipment They include gauges and controlling units to monitor process parameters such as pressure, temperature, and time. Alarms and safety devices would also be included in this category. 

Instrumentation provided for monitoring process parameters dirring treatment of effluent and for the finally treated effluent. 

To operate the MPI or LPI equipment at stable and reprodncable inspection conditions modern units are equipped with a monitoring and control system called "Quality Assurance Package" (termed QAP). The QAP System is ba.sed on an industrial PC with a bus system and field sensors. It ensures that process parameters important for the reproducability of the MPI or LPI are controlled an held between defined limits by a central computer system. It can be adapted to any old system, as well as integrated into new systems. 

For calculation of the volumetric flow rate only the cross section area of the pipe is to be known. In order to give flow under standard conditions the temperature and pressure must be measured, and for conversion to mass flow the composition or density of the gas must be determined. These process parameters are often monitored by calibrated instrumentation. 

Statistical Process Control. A properly miming production process is characterized by the random variation of the process parameters for a series of lots or measurements. The SPG approach is a statistical technique used to monitor variation in a process. If the variation is not random, action is taken to locate and eliminate the cause of the lack of randomness, returning the process or measurement to a state of statistical control, ie, of exhibiting only random variation. 

Monitoring by Electromechanical Instrumentation. According to basic engineering principles, no process can be conducted safely and effectively unless instantaneous information is available about its conditions. AH sterilizers are equipped with gauges, sensors (qv), and timers for the measurement of the various critical process parameters. More and more sterilizers are equipped with computerized control to eliminate the possibiUty of human error. However, electromechanical instmmentation is subject to random breakdowns or drifts from caUbrated settings and requires regular preventive maintenance procedures. 

The assessor should also find out whether an effective testing program is in place to help ensure the serviceability of process measurement equipment. The successful toller should have an established calibration program to address the accuracy of critical measurement equipment. Safety critical process parameters should be monitored and critical process equipment should automatically interlock when monitoring instrumentation detects safety critical deviations. Interlocks should either facilitate a remedy to the critical deviation or bring the process to the zero energy state. These instruments and interlocking devices should be routinely tested to ensure operational reliability. 

Are process parameters monitored and processes and equipment approved ... 

The standard requires controlled conditions to include the monitoring and control of suitable process parameters and product characteristics during production, installation, and servicing. 

The production of some products can be controlled simply by inspection after the product has been produced. In other cases, as with the continuous production of food and drugs, you may need to monitor certain process parameters to be sure of producing conforming product. By observing the variability of certain parameters using control charts, you can determine whether the process is under control within the specified limits. 

The standard requires special processes to be carried out bp qualified operators and/or continuous monitoring and contol of process parameters to ensure that the specified requirements are met. 

With the single-channel method, data are acquired in series or one channel at a time. Normally, a series of data points are established for each machine-train and data are acquired from each point in a measurement route. While this approach is more than adequate for routine monitoring of relatively simple machines, it is based on the assumption that the machine s dynamics and the resultant vibration profile are constant throughout the entire data acquisition process. This approach hinders the ability to evaluate real-time relationships between measurement points on the machine-train and variations in process parameters such as speed, load, pressure, etc. 

These techniques include (1) vibration monitoring (2) thermography, (3) tribology, (4) process parameters, (5) visual inspection and (5) other nondestructive testing techniques. This chapter will provide a description of each of the techniques that should be included in a full capabilities predictive maintenance program for typical plants. 

Many plants do not consider machine or systems efficiency as part of the maintenance responsibility. However, machinery that is not operating within acceptable efficiency parameters severely limits the productivity of many plants. Therefore a comprehensive predictive maintenance program should include routine monitoring of process parameters. 

As an example of the importance of process parameters monitoring, consider a process pump that may be critical to plant operation. Vibration-based predictive maintenance will provide the mechanical condition of the pump and infrared imaging will provide the condition of the electric motor and bearings. Neither provides any indication of the operating efficiency of the pump. Therefore, the pump can be operating at less than 50 per cent efficiency and the predictive maintenance program would not detect the problem. 

Process inefficiencies, like the example, are often the most serious limiting factor in a plant. Their negative impact on plant productivity and profitability is often greater than the total cost of the maintenance operation. However, without regular monitoring of process parameters, many plants do not recognize this unfortunate fact. 

Process parameters monitoring should include all machinery and systems in the plant process that can affect its production capacity. Typical systems include heat exchangers, pumps, filtration, boilers, fans, blowers, and other critical systems. 

Most plants can be cost-effectively monitored using a microprocessor-based system designed to use vibration, process parameters, visual inspection and limited infrared temperature monitoring. 

Acquiring accurate vibration and process data will require several types of transducers. Therefore, the system must be able to accept input from as many different types of transducers as possible. Any limitation of compatible transducers can become a serious limiting factor. This should eliminate systems that will accept inputs from a single type of transducer. Other systems are limited to a relatively small range of transducers that will also prohibit maximum utilization of the system. Selection of the specific transducers required to monitor the mechanical condition, i.e. vibration, and process parameters, i.e. flow, pressure, etc., will also deserve special consideration and will be discussed latter. 

To augment the vibration-based program, you should also schedule the non-vibration tasks. Bearing cap, point-of-use infrared measurements, visual inspections and process parameters monitoring should be conducted in conjunction with the vibration data acquisition. 

The first method required to monitor the operating condition of plant equipment is to trend the relative condition over time. Most of the microprocessor-based systems will provide the means of automatically storing and recalling vibration and process parameters trend data for analysis or hard copies for reports. They will also automatically prepare and print numerous reports that quantify the operating condition at a specific point in time. A few will automatically print trend reports that quantify the change over a selected time frame. All of this is great, but what does it mean ... 

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