| 摘要 |
<p>PROBLEM TO BE SOLVED: To speedy and highly reliably estimate a service life by providing a light intensity measuring process for determining strength of electro-luminescence light, and estimating variation of element current based on time variation of impressed voltage and a cracking interval. SOLUTION: After pressure and temperature in a vacuum container 102 are measured, an SCE element 101 is driven by a driving circuit 108, and element voltage Vf and element current If are measured. After detection of spectrum light by a light detector 114, activating energy Ee and surface temperature T of the SCE element 101 are measured, and a proportional constant (a) is derived from equation I (where Ts is substrate temperature). Impressed voltage Vf is varied, the element current If is measured and is substituted for an equation IV (where a0 is a constant, D is voltage impression length, and (b) is a coefficient), the voltage impression D and the constant a0 are derived. Then, after organic partial pressure is decreased by exhausting gas with a pump 104, the voltage Vf is impressed between element electrodes, the element current If and the surface temperature T are measured, and a coefficient W0 is derived. Life of this SCE element can be estimated from these parameters and equations I-IV.</p> |
