The HydraLite Hydraulic Deadweight Tester is a primary standard that features a re-entrant type measuring piston and cylinder assembly that helps maintain accuracy as the test pressure increases. The HL Series tester is designed for rapid interchanging between high and low pistons and is NIST traceable and accurate to ±0.05% using non-magnetic die-cast alloy or aluminum weights calibrated to international standard gravity at 9.80665 m/s2. A compact screw pump with ratchet handle is easy-to-use. The unit is also available as a deadweight gauge (HLG) for accurate measurements and use as a comparison standard.