什么是SIL認證（液位開關示例）丨您的等級申請是否需要它？
什么是 SIL 認證，它有什么作用？
What is a SIL Certification and What Does It Do?
安裝經(jīng)過 SIL 認證的液位傳感器時，該安裝已通過安全和過程認證。這些在各種標準中定義，例如 IEC 61508，涵蓋電氣、電子和可編程安全相關系統(tǒng)的功能安全。
When installing a SIL certified level sensor, the installation is certified regarding safety and process. These are defined in various standards, such as IEC 61508, that cover functional safety of electrical, electronic and programmable safety related systems.
SIL 系統(tǒng)簡化：
SIL1 – 保證產(chǎn)品始終測量的較低級別
SIL2 – 產(chǎn)品中您不知道的低故障統(tǒng)計風險
SIL3 – 冗余測量能力 – SIL2 和 SIL3 之間的主要區(qū)別之一
SIL4 – 市場上可用的儀器非常少，為此獲得認證的要求極為苛刻。用于例如鐵路電子設備。
The SIL system simplified:
SIL1 – Lower level guarantee that the product will measure all the time
SIL2 – Low statistical risk of failure that you do not know about in the product
SIL3 – Redundant measurement capability – one of the primary differentiators between SIL2 and SIL3
SIL4 – Very few instruments available on the market, and extremely harsh demands to be certified for this. Used e.g. for railways electronics.
制造商基本上可以通過滿足 SIL2 標準和相關 IEC 61508 標準來證明自己，但由外部公司或顧問進行計算時，對風險和性能的真實和客觀評估更為可靠。在這種情況下，方式稱為 FMEDA……
Manufacturers can basically certify themselves by fulfilling the standards of SIL2 and the relevant IEC 61508 standards, but a true and objective evaluation of risk and performance is more reliable when performed by an external company or consultant doing the math. In this case the math is called FMEDA…
什么是 FMEDA？
What is FMEDA?
故障模式、影響和診斷分析是一種全面的分析，將每個單獨的組件都考慮在內。該分析將單個組件的統(tǒng)計數(shù)據(jù)與安裝基礎的所有已知故障、由于產(chǎn)品設計、制造和操作程序（如持續(xù)維護）引起的故障進行比較。
Failure Modes, Effects and Diagnostics Analysis is a thorough analysis that takes every individual component in consideration. The analysis compares the statistics from the individual component with all known failures from the installment base, failures due to product design, manufacturing and operating procedures such as ongoing maintenance.
通過使用外部顧問進行此分析，制造商可以獲得寶貴的工業(yè)統(tǒng)計數(shù)據(jù)和有關產(chǎn)品的許多關鍵問題。這可能會使制造商更難獲得認證，但與此同時，獲取統(tǒng)計數(shù)據(jù)和行業(yè)知識只會使認證更有價值。
By using external consultants for this analysis, the manufacturer achieves access to invaluable industrial statistics and numerous critical questions regarding the product. This might make the certification harder to achieve for the manufacturer, but at the same time, access to statistics and industrial knowledge only makes the certification more valuable.
經(jīng) SIL2 認證的液位傳感器的價值
The Value of a SIL2 Certified Level Sensor
市場上有各種各樣的液位傳感器。其中一些液位傳感器根本沒有經(jīng)過認證，有些經(jīng)過了 SIL1 認證，有些經(jīng)過了 SIL2 認證。通常，經(jīng)過 SIL2 認證的液位傳感器的價格高于經(jīng)過 SIL1 認證或非認證版本的價格，那么什么時候需要花額外的錢來選擇 SIL1 甚至 SIL2 認證的液位傳感器呢？
A wide variety of level sensors are available on the market. Some of these level sensors are not certified at all, some are SIL1 certified and some of them are SIL2 certified. Typically, the price of a SIL2 certified level sensor is higher than the price of the SIL1 certified or non-certified versions, so when is it relevant to spend the extra money and choose a SIL1, or even a SIL2 certified level sensor?
問問自己這些問題：如果浮頂儲罐、化學品儲罐或暴風雨施工儲罐發(fā)生溢出，可以計算哪些費用？花費多少工作時間來檢查工作的設備？您是否因液位開關故障而發(fā)生故障，成本是多少？為了降低風險、提高安全性并同時減少監(jiān)控和驗證液位傳感器是否正常工作的時間，SIL 認證的液位傳感器物有所值。簡而言之，經(jīng)過 SIL 認證的液位傳感器可能比未經(jīng)過 SIL 認證的液位傳感器貴一些，但多出來的錢是在其他領域賺到的。
Ask yourself these questions: What expenses can be calculated if a floating roof tank, a chemical tank or a stormflow construction tank experiences overflow? What number of working hours are spent on checking equipment that works? Have you experienced breakdowns due to level switch failure, and what were the costs? To lower the risk, increase safety and at the same time decrease hours spent on monitoring and verifying that the level sensors work correctly, a SIL certified level sensor is worth the value. In short, a SIL certified level sensor might be a bit pricier than a level sensor that is not SIL certified, but the extra money spent are earned in other areas.
對于許多過程工業(yè)應用，工程師熟悉危險區(qū)域的認證。這些是眾所周知的要求，可確保電氣設備在潛在爆炸性環(huán)境中的安全運行。為了確保儀器的可靠性并正常運行，經(jīng)過 SIL 認證的液位傳感器是確保工作流程自動化的重要步驟。此外，使用經(jīng)過 SIL2 認證的液位傳感器可確保每個單獨組件的質量，并根據(jù)已安裝儀器的經(jīng)驗來保持這一點。
For many process industry applications Engineers are familiar with hazardous area approvals. These are well known requirements ensuring the safe operation of electrical equipment in potentially explosive environments. For reliability and to ensure proper operation of your instrumentation, a SIL certified level sensor is an important step in securing the automation of the workflow. Furthermore, using a SIL2 certified level sensor ensures the quality of every individual component and holds this up against experience from an installed base of instruments.
不僅僅是技術知識
More than Technical Knowledge
除了徹底的技術分析外，SIL2 認證還需要自動產(chǎn)品驗證。這意味著液位開關能夠自動運行測試，以電子方式驗證測量儀器是否按預期工作。如果測試結果為異常，自動驗證功能將自動提醒工作人員。此功能對遠程應用程序或由于位置而不易監(jiān)控的應用程序特別有用。此功能可以稱為浪費保護——它可以防止浪費工作時間來檢查有效的設備，并使工作人員能夠更有效地專注于工作日。
Besides the thorough technical analysis, a SIL2 certification also demands an automatic product verification. This means that a level switch is capable of automatically running tests to electronically verify that the measuring instrument works as intended. If the test comes out with a negative result the auto-verify functionality will automatically alert the staff. This feature is especially beneficial on remote applications, or applications that are not easily monitored due to location. This functionality could be named a waste-protection – it protects from wasting working hours on checking equipment that works and allows the personnel a more efficient focus on a working day.
