The Ametek DM-T-50/OIL Type T Hydraulic Deadweight Tester, Distilled Water/Alcohol Medium; 10-5000 psi is a dead weight tester that offers laboratory accuracy in an instrument designed to withstand an industrial environment or daily stresses of a manufacturing environment. Each tester features a re-entrant type measuring piston and cylinder assembly. This design reduces the rate of fluid leakage and increases float time, helping to maintain accuracy as test pressures increase. This model offers a range up to 5,000 psi. This robust tester has been engineered to withstand the stresses of daily operation in a manufacturing environment and still maintain its accuracy and repeatability. The Type T is constructed of 300 series stainless steel and Monel and is supplied with Buna N O-rings as a standard unit. This deadweight can use a water/alcohol mix or hydraulic oils for the pressure medium. The DM-T-50 model offers accuracy of ±0.015% of reading. The accuracy stated is the over-all accuracy of the tester. The accuracy takes into account linearity, hysteresis, and repeatability. It would also account for intrinsic corrections. Site corrections are the user's responsibility and the unit will not perform as specified without them. The testers are manufactured to either International Standard Gravity of 9.80665 m/s2 or to a user specified local gravity.

Re-entrant piston/cylinders

The Type T deadweight employs a re-entrant type piston/cylinder assembly. This design applies test fluid to the outside and inside of the cylinder. Unlike a simple piston/cylinder, this configuration reduces clearance between the piston and cylinder as pressure increases. This reduces the rate of fluid leakage and increases float time, offers the technician more time for testing, and reduces the amount of pumping necessary to sustain the fluid loss.

Overhung weight carriers

Another feature of Type T deadweight tester is the way that the weights are positioned on the carrier. M&G utilizes an overhung weight carrier design. This design employs a tube carrier that is positioned over the column and onto the piston driver. The center of gravity for the stack of weights is lowered, reducing side thrust and friction; which lengthens the life of the piston/cylinder assembly. This also improves measurement accuracy.

Protected piston/cylinder

The piston and cylinder assembly are enclosed in the column of the tester. The weight carrier floats on the piston driver preventing damage to the piston/cylinder assembly. Additionally, the piston/cylinder assembly is engineered with positive over-pressure protection by restricting vertical movement. This protects the assembly from damage in the event of weight removal under pressure.

Dual volume pump

The Type T pump offers a dual volume pumping feature that allows for large volume of fluid to be added at low pressures to fill the system and increase pressure rapidly. Once the system is filled, output volume can be switched to a smaller volume. This eases pumping and also provides for finer control in higher pressure ranges. The reservoir is kept at atmospheric pressure meaning that the tester can also be refilled during a calibration run.

Easy Leveling

Ametek floating ball testers incorporate a bulls-eye level for reference when preparing the unit for use. The tester also employs a 3-leg leveling system which is more convenient and is superior to a 4-leg system.