Relpaced the flammable gas detectors in the right and left shield hut as well as the gas shed. The right and left shield hut gas detectors are calibrated to 50% methane "LEL". The gas detector in the gas shed need to be looked at more in-depth before its adjusted to 50% methane "LEL" it currently has a problem with the settings fluctuating. All the flammable gas detectors are working as they should. If an alarm occurs, on the panel in the counting house, please contact Hall-A staff.