Spectrometer as a sensor
Spectrometer as a Sensor
Combining the proven benefits of diode-array spectrometer technology with the assets of an updatefree and low-maintenance hard- and software, a tecSaaS®-based embedded spectrometer fulfills highest requirements in terms of resilience [temperature, moisture, vibration, …] and availability for use in industrial [machinery] or mobile [field] applications.
With complete integration of the data processing functions into the spectrometer unit, process relevant results can be transferred directly to the machine or process control system - the [Windows-] PC is obsolete. For data evaluation, the integrated embedded controller even offers complex algorithms such as chemometrics or FFT and allows to define customized mathematical processing using the integrated formula parser.
Parameterization of software instead of programming and a pool of hardware modules make the implementation of a stand-alone embedded system fast and efficient – significantly shortening the time from the idea up to its productive use.
The operation of the embedded spectroscopy system generates measurement results which are communicated through a process interface to the manufacturing control system. In the conception of industry 4.0, some of the data may be passed to further internal or external communication layers e.g. for data access or cloud storage. In addition, a temporary connection to a PC is used for parameter setting and monitoring purposes.
Facing the fact that these interfaces are vital for the embedded spectroscopy system, a sound concept for the protection of the instrument against cyber-attacks and -threats has to be implemented.
In the first place, the communication interfaces of the tecSaaS® platform and the paths for access are limited to the ones which are absolutely required. In addition, to provide a suitable level of protection, up-to-date and robust methods of encryption and hashing were implemented for the authentication and signing of users and data files [SHA-2 and RSA].
Protection against unauthorized access is realized by several user login levels, each of them with suitable permissions and obligatory password. In this way, the administration of the device and its measurement methods can be effectively limited to persons actually entitled to perform these operations.
An authentication in intervals is used for communication with the monitoring and parameterization tool [MPT] software on a PC. Local pairs of encryption keys are generated by random numbers, produced by the instrument. In this way, it is not possible to gain access to instruments by deducting the key from a known hardware property.
UV-VIS-NIR spectrometer and photometer systems have been used in process and mobile [field] applications for many years. Optical measurements are fast, non-contact and require little maintenance. The spectral information gives a deep insight into a process or the status of agricultural parameters.
A new generation of smart embedded sensor systems has been introduced recently to make use of even more reliable and stable systems by eliminating the requirement for a PC to acquire, evaluate and process the spectral data. [Philosophy]
A wide variety of applications benefit from an embedded spectrometer unit. As a technology platform, it is not limited to a particular industry or application. It is an attractive option whenever there is the requirement for a reliable, compact UV-VIS-NIR sensor which needs to be integrated into a process or machine network.
Embedded spectroscopy systems have been introduced, e.g. in agriculture, to determine dry matter and additional ingredients on harvesting machines, plant reflection for selective fertilizer output, in an NIR manure sensing system for liquid manure distribution tanks, for soil sensing and in other measurement tasks.
In the coating industry, embedded spectrometer systems monitor the optical properties or the thickness of applied layers during production. Online concentration measurements of etching and plating bath parameters are performed in the galvanic and semiconductor industries to assure optimum product quality.
There are many more projects going on to implement this innovative technology!
(Process Analytical Technology)
The term Process Analytical Technology [PAT] has been originally defined by the United States Food and Drug Administration [FDA] but is now often used for process analytics in general. It describes the approach to better understand the manufacturing process by using analytical measurements and, ultimately, to produce better product quality and reduce waste. The tools used to collect and analyze the measurements are often in-line and on-line fiber-optic spectrometer systems for the UV-VIS and NIR [near infrared spectroscopy, color] but also include Raman spectroscopy and others.
In the chemical and pharmaceutical industry, these systems are used to control the process and detect end-points by measuring the concentration of active ingredients and parameters like color, water content, OH-numbers or similar. Other industries include the lighting and optical industry, food, beverage, and semiconductor [e.g. optical wafer inspection].
An embedded spectroscopic sensor system can be directly connected to the industrial data infrastructure by means of a selection of process communication interfaces and field buses such as Modbus, CANbus or EtherCat. This allows to implement a closed-loop control [Process Interface].
In combination with powerful data evaluation algorithms like multivariate analysis [chemometrics], multiple parameters can be measured in reactors or pipes. The embedded spectroscopy platform also provides on-board filter algorithms which check the validity of the spectral data, detecting and eliminating corrupted spectra caused by bubbles or particles, as well as an empty pipe status.
In addition to functionality and reliability of the embedded instrument used in process analysis, IT security has to be considered especially in an industry 4.0 environment [Security].
In the conception of industry 4.0, sensors in production and quality control applications make their results available in the industrial network. In addition to the general requirements for a system operating in an industrial environment, the huge potential of this networked approach must be accompanied by a suitable security concept to prevent malfunction resulting in possibly severe consequences to production, material or humans. Such failure could be caused by mishandling, manipulation or other threats arising from the permanent connection of the industrial sensor within the fab.
Even though 100% security is not achievable, the tecSaaS® embedded system was designed with an IT security concept to achieve a high level of protection. The embedded concept starts with a closed system based on dedicated hardware and non-standard firmware provides a basis of intrinsic security, because its architectural details are not known to the public. It is thus not possible to simply port malware to the tecSaaS® platform. In addition, a proprietary protocol combined with state-of-the-art technologies like encryption and authentication result in a system with low vulnerability to these kinds of threats.
The closed ecosystem provides a level of protection that does not depend on frequent updates and patches, which may cause excess effort for maintenance or service to prevent failures resulting in financial or personal damage.
Distributed sensors, data processing on-board, fast, reliable and maintenance free – that’s the idea of embedded spectroscopy.
For decades, spectroscopy for industrial applications was inherently linked to PC technology and Windows operating systems, because nearly all generic sensor hardware and software was designed for PC technology, which is driven from products for consumers.
The work on a generic embedded platform for spectroscopy, which is as powerful as PC-based solutions was obvious but this needed significant development. Even interfaces like USB, which was never designed for reliable industrial applications, became state-of-the-art in industrial environments.
Embedded spectroscopy, with its special demands, became realistic because of the recent developments in data processing capabilities, combined with low power consumption and the availability of data processing components for industrial requirements.
To specify such a product idea with all the restrictions, advantages and disadvantages is challenging work and forces you with aspects you never face on a PC and Windows operating system. Security and reliability becomes a strong focus and leads to specialized operating systems and well selected 3rd party modules.
Furthermore, parametrization an application instead of programming it, is a feature customers are used to if they work with Windows based software packages for spectroscopy. That makes the difference between a generic platform with fast time to market, in comparison to a special instrument software, coded for one application with closed algorithms [Parametrization vs. Programming]. But, it means also to protect the customer IP [system setup and algorithms] and make the system save for unwelcome access, competitors or hacking [Security].
Spectrometer as a Sensor – which is the idea of distributed systems with on-board data processing capabilities, doesn’t need an Man-Machine-Interface or sophisticated user interface. Such a system communicates remotely with tools for monitoring and setup and more important with process management systems via standardized communication interfaces [Process Interface]. That an important specification for the selection of the operating system and 3rd party code libraries.
No Programming Required
Embedded spectroscopy systems allow to create distributed sensors with internal data processing, adding the potential for fast, reliable and maintenance-free operation.
On the other hand, the user is familiar with the convenient operation of a PC-based spectroscopy system with powerful Windows software: a selection of functions and parameters is readily available for powerful spectral data processing and result calculations.. In contrast to embedded programming, the simplified setup and parameter setting of the hardware is the key advantage of a generic platformover a special instrument software, coded for one application with closed algorithms. This ease of operation makes a highly skilled programmer unnecessary and thus strongly shortens the time required for setup or time-to-market. Also, no additional protection of the IP [setup and algorithms] is required, making it safe against unwelcome access and competitors [Security].
To setup and monitor such a system, tools for different demands and occasions are provided. For setting up and detailed monitoring of a process, a powerful tool has to be provided, running in the usual environment, a PC [product information MPT]. To support a periodic monitoring it is convenient to use an APP for tablet or smartphones or a web server interface.