## 6 Conclusions  
Detectors are a key issue of the contemporary scientific approach to CH, both for diagnostics and conservation. INFN has always been developing detectors and instrumentation and INFN-CHNet, which has inherited this philosophy, keeps developing and applying new instrumentation to the study of CH. In the paper, an overview of the most used detector-based techniques in the INFN-CHNet network has been provided. As described above, the research activity carried by INFN-CHNet aims at developing optimized setups for spectrometric techniques, which use both traditional state-of-the-art and highly innovative detectors. As for the former, examples are PIXE, XRF, XRD, XCT (X-rays), PIGE, PGNAA (gamma rays), UV-VIS-IR (light), and MS spectrometers (particles). For these techniques, measurement setups have been tailored for CH applications optimizing performances, reliability, weight, transportability, cost, absorbed power, integrability and complementarity with other techniques. So, focusing on the INFN-CHNet laboratories, we now find instruments purposely optimized/designed for CH measurements, such as multi-detector PIXE setups, little and easily transportable MA-XRF scanners for elemental imaging, \(\mu\)-X-ray Diffractometers, transportable X-ray tomographs, very compact and light CdTe detectors, with interesting performances in high-energy X-ray/low-energy gamma-ray detection, portable XRL spectrometers, spectrophotometers and spectroradiometers, macro-FT-IR/single point micro-FT-IR/mapping-IR spectrometers, MS and AMS systems. Regarding innovative detectors, we can remember highly innovative detectors specifically developed within INFN-CHNet, such as ARDESIA, the monolithic array of SDD detectors for XAS studies at the INFN-LNF DA\(\Phi\)NE-Light synchrotron radiation facility, the MAXRS detection setup at the low-energy Riken-RAL muon beam and the PGNAA/neutron-imaging facilities at the LENA Laboratory. Together with the description of the used experimental setups, paths for next-generation instruments have been suggested, when possible, as in the case of X-ray Superconductive Detectors and X-ray Microcalorimeter Spectrometers, which open up new, exciting perspectives, as they enable exploring CH with astonishing improvement in energy resolution with respect to the values of standard X-ray detectors. As we have shown in this review, the study, characterization, and conservation of CH are closely interlaced with detector design, implementation, and use. Many issues in CH can now be addressed thanks to scientific techniques exploiting the existing detectors. However, several questions still remain unresolved; R&D of new techniques/new detectors and the optimization of the existing devices is driven by the necessity to answer those questions. Conceptualization, L.G. ([PERSON]), L.C., F.T. and M.M. ; methodology and writing--original draft preparation, F.T., L.G. ([PERSON]), L.C., N.G., and M.M. ; PIXE-PIGE, L.T., P.B., A.F., S.B.L., C.R., A.M., C.C., G.P. and F.T. ; XRF, A.B. and M.C.G. ; XRF-synchrotron; G.P., XRD; F.A., M.B. ([PERSON]), R.B., and M.P.M. ; XCT, M.B. ([PERSON]), M.C. ([PERSON]), D.D.M., M.C. ( [PERSON]), V.S., P.O., MAXRS; D.A. and M.C. ([PERSON]), A.S., B.S., M.P., S.A. ([PERSON]), PGNAA; [PERSON]. ([PERSON]), A.L.G., A.R., and L.S., luminescence; A.M.G., S.P., G.S., photometry and colorimetry; M.C.G., L.P., M.R., FFI-IR; FG. ([PERSON]) and N.G., neutrons; F.M. and S.N., HR-ICP-MS; F.M. and S.N., TIMS; C.L. and S.A. ([PERSON]), IRMS; L.T., and V.G., ToF SIMS; M.F., L.L., S.B., and F.T., AMS; Writing--review and editing L.C., L.G. ([PERSON]), N.G., F.G. ([PERSON]) and M.M. ; supervision, L.G. ([PERSON]), L.C. and M.M. All authors have read and agreed to the published version of the manuscript. This research did not receive any external funding. Not applicable. [PERSON] is warmly acknowledged for his significant technical contributions and suggestions. The authors declare no conflict of interest.