A hand-held flow metering device for dispensing a pressurized fluid comprises a valve, a flow meter, a trigger lever, a trigger release mechanism and meter electronics. The valve is connected to the pressurized fluid to regulate flow of the pressurized fluid through the device. The flow meter is disposed within the flow of pressurized fluid to measure volumetric flow of the pressurized fluid. The trigger lever is configured to be manually displaced to mechanically open the valve. The trigger release mechanism is connected to the trigger lever and is selectively actuated to mechanically prevent the trigger lever from opening the valve when the trigger lever is displaced. The meter electronics is connected to the flow meter and the trigger release mechanism to actuate the trigger release mechanism based on output of the flow meter.