This work aimed to compare two systems used for ammonia emission monitoring in broiler houses. The low cost PMU (Portable Monitoring Unit), and MAEMU (Mobile Air Emission Monitoring Unit) are systems used for ammonia concentration monitoring and, with broiler house ventilation rate, ammonia emission rate (ER) can be calculated. The accuracy of ammonia emission rate calculated with data from the PMU using a simplified calculation algorithm was quantified using the MAEMU as a standard.