Recently, the Istituto Nazionale di Astrofisica (INAF) has placed a contract with Hamamatsu Photonics to acquire hundreds of Silicon Photomultipliers (SiPM) tiles to build 10 cameras with 37 tiles each for the ASTRI Mini-Array (MA) project. Each tile is made up of 8 $\times$ 8 pixels of 7 $\times$ 7 mm² with micro-cells of $75\mathrm{\mu }\mathrm{m}$. To check the quality of the delivered tiles a complex and accurate test plan has been studied. The possibility to simultaneously analyse as many pixels as possible becomes of crucial importance.

Dark Count Rate (DCR) versus over-voltage and versus temperature and Optical Cross Talk (OCT) versus over-voltage can be easily measured simultaneously for all pixels because they are carried out in dark conditions. On the contrary, simultaneous Photon Detection Efficiency (PDE) measurement of all pixels of a tile is not easily achievable and needs an appropriate optical set-up. Simultaneous measurements have the advantage of speeding up the entire procedure and enabling quick PDE comparison of all the tile pixels.

The paper describes the preliminary steps to guarantee an accurate absolute PDE measurement and the investigation the capability of the electronics to obtain simultaneous PDE measurements. It also demonstrates the possibility of using a calibrated SiPM as reference detector instead of a calibrated photodiode. The method to achieve accurate absolute PDE of four central pixels of a tile is also described.

最近，意大利国家航空航天研究所（INAF）与Hamamatsu Photonics签订了一项合同，以收购数百个硅光电倍增管（SiPM）磁贴，为应科院微型阵列（MA）项目制造10台相机，每个摄像头含37个磁贴。每个图块由8个组成$\times$ 8像素的7 $\times$7 mm ^2，带微孔$75\mathrm{\mu }\mathrm{米}$。为了检查交付的瓷砖的质量，已经研究了一个复杂而准确的测试计划。同时分析尽可能多的像素的可能性变得至关重要。

暗计数率（DCR）与过电压和温度之间的关系以及光串扰（OCT）与过电压之间的关系可以轻松地同时测量所有像素，因为它们是在黑暗条件下进行的。相反，不容易实现对瓦片的所有像素的同时光子检测效率（PDE）测量，并且需要适当的光学设置。同时测量的优点是可以加快整个过程，并可以对所有图块像素进行快速PDE比较。

本文介绍了保证准确的绝对PDE测量的初步步骤，并介绍了电子设备获得同步PDE测量的能力。它还演示了使用校准的SiPM作为参考检测器代替校准的光电二极管的可能性。还描述了实现图块的四个中心像素的精确绝对PDE的方法。