Key performance parameters of the X-ray Monitor JEM-X
| Parameter | Value |
| Energy range | 3 - 35 keV |
| Detector area | 500 cm^2 (1 unit) |
| Energy resolution | 1.3 keV @ 10 keV |
| Field of view | 4.8 deg (dia) fully coded FOV |
| Angular resolution | 3 arcmin |
| Continuum sensitivity
(3 sigma in 10**5 s, @ 6 keV, dE=0.5E) |
1.2 x E-4 ph/(s cm² keV) |
| Line sensitivity
(3 sigma in 10**5 s, @ 6 keV) |
1.6 x E-4 ph/(s cm²) |
| Timing accuracy
(3 sigma) |
122 micro-s |
| Source location (15 sigma isolated source) | < 1' (90% confidence) |