The design intention of the PMI system
PMI 系統有助於改善主機工況，提升燃油經濟性，發現主機運轉過程之中的異常。經過長時間發展及改進，目前PMI系統已經成為ME主機的標配。
In a word, the PMI system is beneficial to improve the performance condition of main engine, improve fuel economy, and find abnormalities during the main engine running.
After a long period of development and improvement, the PMI system has already been the standard configuration of the ME engine.
Pmax 目前一共應用2款，分別為ABB及Kistler生產，
ABB宣稱不需要定期做calibration，設計上ABB sensor與示功考克一體，不可單獨更換。
Kistler理論上滿足加裝要求，sensor與示功考克分開設計，
按照Kistler要求，calibration週期為4~6月/次，
IMO要求該sensor每年至少calibration一次，
因此，船上目前安裝的多為Kistler版本。
Pmax is currently set 2 types, which are manufactured by ABB and Kistler . As above photo shown, ABB claims that there is no need for regular calibration during overall life cycle . The ABB type is integrated design with indicator cock, and cannot be replaced separately. Kistler satisfied theoretically the requirements of modification. The sensor and the indicator are designed separately. As Kistler`s instruction, the calibration cycle should been under 4-6 months. IMO requires the sensor should be calibrated annually. Therefore, the most versions choice were found be Kistler version.
根據SL-621, Pmax sensor外部包裹有保溫防護層，若丟失保溫層，sensor暴露於外部環境中，外部溫度過低，易導致低溫腐蝕，損壞sensor，所以，外部保溫層非常重要，不可丟失；
As SL-621 shown, the Pmax sensor is wrapped with insulation layer. If the insulation layer is lost, the sensor is exposed to the external environment. If the external temperature is lower than inner space, is’s easily found damaged which caused by low-temperature corrosion, Therefore, the external insulation layer is very important and cannot be lost.
根據SL-658，主機運轉過程中，千萬不可打開示功考克，即使考克漏氣也不被允許，否則極有可能導致Pmax sensor損壞，offline設備使用時，必須先接好coupling再開啟考克，日常運轉中，考克的cover螺帽保持關閉。
As SL-658 shown, the indicator cock should never be opened during the engine is running even if the cock leakage, otherwise it is very likely to damage the Pmax sensor.
During the offline device connected, you have to connect the coupling firstly, then turn on the cock, the cover nut of cock should be closed during daily operation.
故，主機啟動時，示功閥開啟，不可選用Air Run吹車，只能選用slow turn吹車，況且從安全角度講，主機吹車尤其是長時間不動主機情況下，吹車應當選用slow turn，時間及次數可適當多一些，關於slow turn吹車耗費空氣量大的說法，有一定的根據，但只是表明操作者吹車時想達到主機發火轉速，小流量slow turn閥，大流量示功考克洩氣，耗氣量肯定大一些（相同執行時間下，slow turn耗氣量小一些）但吹車的目的不在轉速，而在於主機目前轉動正常，缸內無異物，具備起車條件而已，slow turn才是正確的吹車方式。
In conclusion, during the main engine prepared standby cycle, the indicator valve is opened. Do not blow the engine with “Air Run” mode, only “Slow Turn” mode should be carried out. Moreover,the main engine should carry out blowing the engine with slow turn mode under long time engine stay , The operating times and blowing period can be kept longer appropriately. There is a certain basis for the argument that slow turn blowing will consumes more air, but it only indicates that the operator wants to reach the ignition revolution of the main engine during engine blowing, the less flow slow turn valve with indicator cock vented, the blowing air consumption may be larger (the air consumption were less than Air run under the same execution time with same operating period), but the purpose of engine blowing were not revolution speed, it should be confirmed no foreign matter in the cylinder liner space and rotation system in normal condition, finally confirmed the engine preparation for starting were available. The correct mode of engine blowing should been in slow turn.
PMI Auto-tuning
PMI Auto-tuning 必須基於以FQA調整主機MOP顯示負荷（設定負荷）與PMI計算所得實際負荷相等！
PMI Auto-tuning 目的在於控制排放及降低油耗，Pmax 增加1bar，油耗降低0.2~0.3g/kwh.
PMI Auto-tuning must be based on adjusting the engine MOP display load (set point) with FQA to be equal to the actual load calculated by PMI(estimated load)!
The purpose of PMI Auto-tuning is to control emissions and reduce fuel consumption. Pmax is increased by 1 bar and fuel consumption is reduced by 0.2~0.3g/kwh.
CoCoS-EDS:
早期的版本（basic）不能與別的系統通訊，後期的系統相當於主機的VDR，可以備份所有主機運轉的alarm及正常數據，為遠程數據分析提供了基礎。
The early version (basic) cannot communicate with other systems. The later version is equivalent to the engine’s VDR, which can back up all the alarms and normal data of the engine’s operation, providing a basis for remote data analysis.