自從上次Keith Shuttleworth先生做客天津盛源科技有限公司為大家深入講解EN285標準，我們收到很多學員提出的問題，在此為大家整理出幾個具有代表性的問題進行展示：
01
Question:
Is there a certain order to be followed when we perform a steam quality test?
問：
蒸汽質量檢測3個參數執行的順序？
Answer:
The order in EN 285 is 1.Non-condensable gases, 2.Dryness and 3.Superheat test. There is no engineering or logical reason why this order is required, though we tend to follow this order when we carry out and report tests. Because of the way the test points on the test elbow are used we often carry out the non-condensable gas test and the dryness test at the same time.
答：
EN 285中的順序為1.不凝性氣體，2.干燥和3.過熱測試。盡管需要在執行和報告測試時遵循該順序，但沒有工程或邏輯上的理由要求執行此順序。由于使用測試彎頭上的測試點的位置關系，我們經常同時進行不凝性氣體測試和干燥度測試。
02
Question:
How do we solve the poor repeatability when perform a dryness test?
問：
如何解決干度值測試中重現性差的問題？
Answer:
For the results to be repeatable, the test method should also be repeatable. Simply following EN 285 will not allow this! Because the calculation we use does not take account of heat losses to the environment, the longer the test proceeds, the worse the result tends to be. To carry out the test repeatably, the amount of water used to fill the flask should be as close to being identical between tests and the temperature of the water used should also be close from test to test. Provided that this is the case and the end temperature for the ending the test is the same (before agitation of the flask). Another factor is that the insertion depth of the temperature sensor into the flask should also be the same between tests.
答：
想要獲得具有重現性的測試結果，要求測試方法保持重現性。單純地遵循EN285要求的檢測方法無法做到這一點。因為我們使用的計算沒有考慮環境的熱損失，所以測試進行的時間越長，結果就越糟。為了重復進行測試，在兩次測試之間填充燒瓶的水量應盡可能接近相同，并且每次測試所用的水溫也應接近。在這種情況下，并且結束測試的最終溫度是相同的（在攪拌燒瓶之前）。另一個因素是溫度傳感器在燒瓶中的插入深度在兩次測試之間也應相同。
EN 285 specifies that the flask fill volume should be 650ml +/-50ml. We would suggest 650ml +/-20ml. EN 285 specifies the water temperature should be between 0 and 27℃. We believe that the water temperature should be close to ambient the starting temperature +/-2℃ between tests. We always remove steam from the flask the very first reading we get that indicates that the water is 80℃. We then agitate the flask to get a homogeneous temperature reading.
EN 285規定燒瓶中水的填充量應為650ml +/-50ml。但是再實際操作中我更建議將這個范圍所縮小到650ml +/-20ml。EN 285規定水溫應在0到27℃之間。我認為測試之間的初始水溫應接近環境溫度，偏差在+/-2℃之內。我們始終會在獲得第一個讀數時即從燒瓶中除去蒸汽，這表明水為80℃。然后，我們攪拌燒瓶以獲得均勻的溫度讀數。
If you consider the extreme cases which are in accordance with EN 285, one could be that the flask is filled to 700ml with ice cold water. The other is that the flask is filled to 600ml with water at 27℃. To heat the different amounts of water from different starting temperatures means that the tow tests will take different times and you will get different results because of the unmeasured heat losses to the environment
如果考慮符合EN 285的極端情況，則可能是用冰冷的水將燒瓶裝滿700ml。另一個是將燒瓶在27℃的水中加滿600ml。從不同的起始溫度加熱不同量的水意味測試將花費不同的時間，并且由于對環境的不可估量的熱量損失，用戶將獲得不同的結果。
03
Question:
Where should the samples be taken from for the tests?
問：
應該從哪里獲取樣品進行測試？
Answer:
The tests are of the steam supply to the sterilizer and not of the steam within the sterilizer. The samples should be taken on the individual supply pipes to each sterilizer between the steam distribution system and the steam on/off valve for the sterilizers. Also, the tests should be carried out on every sterilizer and not groups of sterilizers from a single test point.
答：
測試是針對供應到滅菌器的蒸汽，而不是滅菌器內的蒸汽。樣品應在蒸汽分配系統和滅菌器的蒸汽開/關閥之間的各個滅菌器的單獨供應管道上采集。另外，應在每個滅菌器上進行測試，而不應從單個測試點對滅菌器組進行測試。
A sample point is required which has be installed into the steam pipework if test points for the tests are not included within the sterilizer pipework design. We call this a steam quality test elbow and it should be the same size as the pipe supplying the sterilizer with steam.
如果在滅菌器管道系統設計中未包含測試點，則需要將其安裝到蒸汽管道中。我們稱其為蒸汽質量測試彎頭，其尺寸應與向消毒器供應蒸汽的管道的尺寸相同。
The sample for non-condensable gases is taken from the top of a horizontal pipe, the sample for the dryness and superheat tests is taken from a pitot tube which is inserted into the flow of steam and a steam temperature sensor is installed. The location of this is less important than the other two which are really mandatory.
不可冷凝氣體的樣品取自水平管的頂部，干燥和過熱測試的樣品取自皮托管，該皮托管插入蒸汽流中，并安裝了蒸汽溫度傳感器。它的位置不如其他兩個重要，其他兩個是強制的。
04
Question:
When in the process cycle should the sample be taken?
問：
滅菌循環中應該何時取樣？
Answer:
The steam quality tests are started when steam enters the sterilizer chamber for the first time. The description is exact and does not mean when the sterilizer enters the heating phase or when the sterilization stage commences, but when steam enters the chamber for the very first time. This is usually on completion of the first vacuum pulse during air removal. This is deemed to be the worst case condition, because the chamber is at its coolest and is likely to result in the greatest steam demand.
答：
當蒸汽首次進入滅菌室時，將開始蒸汽質量測試。該描述是準確的，并不意味著滅菌器何時進入加熱階段或何時開始滅菌階段，而是蒸汽首次進入腔室時的描述。這通常是在排氣期間完成第一個真空脈沖時完成的。這被認為是最壞的情況，因為腔室處于最冷的狀態，并可能導致最大的蒸汽需求。
The end point of each test is provided in the test methods and are not expected to occur in the first steam pulse and will include periods where the sterilizer is pulling a vacuum. This can be anticipated and does not represent a problem. When the test is completed, the cycle can be aborted ready for the next test.
在測試方法中提供了每個測試的終點，并且預計不會在第一個蒸汽脈沖中發生，并且將包括滅菌器抽真空的時間段。這是可以預期的，并不代表問題。測試完成后，可以中止循環，以準備進行下一個測試。
Because logically, there is only one point in a cycle where steam enters for the first time, if you wish to run three dryness or non-condensable gas tests, you need to start three cycles for each of the two tests.
從邏輯上講，在一個循環中只有一個點是第一次進入蒸汽，因此，如果您要進行三個干燥或不可凝性氣體測試，則需要為兩個測試中的每個啟動三個循環。
This picture which is a pressure trace of a sterilization process, shows where steam enters the chamber for the first time. To be aware of this, someone needs to be watching the chamber pressure display, though with experience, you will probably be able to hear steam entering the chamber.
該圖片顯示的是滅菌器滅菌過程的壓力曲線，顯示了蒸汽首次進入腔室的位置。要知道這一點，有人需要觀察箱內壓力顯示，盡管有經驗，您可能會聽到蒸汽進入箱內。
05
Question:
Is it normal when I get negative figure from superheat test?
問：
過熱值為負數正常嗎？
Answer:
The acceptance criteria for the superheat test is that the temperature measured in the expansion tube is less than 25°C above the boiling point at the local environmental pressure – 100°C at sea level.
答：
過熱測試的可接受標準是，膨脹管中測得的溫度在當地環境壓力下比沸點海平面溫度100度，高出25°C以下。
This test always seems to pass these criteria without any problem. What concerns many however is that the results obtained are often below 100°C which is counter intuitive, if you are aware of the theory of the test.
該測試似乎總是通過這些標準而沒有任何問題。但是，讓許多人擔心的是，如果您了解測試的原理，那么獲得的結果通常會低于100°C，這是非常直觀的。
The answer to this lies in the test design, which assumes theory and practice will coincide exactly. When steam flows from an orifice, it results in a low pressure area close to it. This results in steam which has condensed on the wall of the expansion tube to be sucked towards the orifice and where it gets entrained into the steam flow. This results in the low temperatures experienced and is a function of the test method and not the person conducting the test. For this reason, there is little point in conducting three superheat tests as they always pass.
答案在于測試設計，它假設理論和實踐將完全一致。當蒸汽從孔口流出時，會在其附近形成低壓區。這導致冷凝在膨脹管壁上的蒸汽被吸向孔口，并被夾帶到蒸汽流中。這會導致測試溫度降低，這是測試方法導致的，而不是測試人員。因此，進行三個過熱測試總是可以通過的。
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