▎ 摘　　要

In this paper, graphene nanosheets were used to detect ammonia gas (NH3). Graphene dispersion was drop cast on special ceramic substrate to fabricate the gas sensor. The measurements were based on measuring the resistance before and after the gas exposure. A considerable increase in the resistance after gas exposure was found. Resistance increased from 1.4 k Omega to 1.8 k Omega just in less than 3 s. Recovery time is also determined at room temperature and it was 2 h. The delay in recovery time was ascribed to the fact that desorption is slower than the adsorption. Response to ammonia gas is calculated and demonstrates a maximum response of 198.6% after about 5 min.