G.A.STTP Gas Allocation System Meter
The G.A.S.TTP heat allocation meter is a version of the standard G.A.S.TT meter designed for use in baseboard hydronic heating systems that employ non-electric (pneumatic or Danfoss style) zone valves. The G.A.S.TTP meter uses the proven G.A.S.TT hardware design but employs two thermistor temperature sensors and proprietary firmware algorithm to accurately meter variable water flow water flow rate systems from 0.1gpm to 5gpm. Non-electric zone valve systems modulate water flow to the apartment over this range to depending upon thermostat setting and heating demand. The G.A.S.TTP meter uses two pipe-mounted sensors to accurately measure BTUH for the entire apartment heating loop - one installed at the mid-point of the loop - the second at ¼ loop length from the loop inlet.
The G.A.S.TTP is not connected to the zone valve but uses a built in 90°F threshold in firmware to initiate data collection. Since both meter thermistors are mounted some distance apart (usually 5 - 10 feet) near the mid-point of the hydronic loop, the meter is usually located in the living room area of the apartment and is normally installed at baseboard level adjacent to the hydronic element. The use of two pipe-mounted sensors and the firmware algorithm effectively meter the hydronic loop in forward and rear sections separately and then combine both for total BTUH heat output. This method is highly accurate and is essential for measurement of BTUH for water flow rates below 0.5gpm encountered in modulated water flow systems
The G.A.S.TTP includes tamper detection circuitry which detects resident tampering, battery failure or meter failure to facilitate meter servicing. Time -Temperature data output is directly compatible with the standard G.A.S.TT allocation meter.