10 to 20 times more accurate than non-deadweight systems
YORK, Pa. (GLOBE NEWSWIRE) — Morehouse Instrument Company has added a 30,000 lbf automatic deadweight load cell calibrator to its laboratory to dramatically improve force calibration accuracy. The 30,000 lbf machine expands the wide range of calibration equipment at Morehouse, which includes a 120,000 lbf, 12,000 lbf, 1,100 lbf, and 120 lbf deadweight machine.
“Our goal was to achieve more accurate calibrations by designing and building a machine to the highest standards,” notes Henry Zumbrun, President of Morehouse. “We accomplished this with a machine that is plumb, level, square, more rigid and has lower torsion than other deadweight machines. Getting all these aspects right is essential to manufacturing a great force standard capable of producing very repeatable results for our customers.”
The new 30,000 lbf deadweight machine is 10 to 20 times more accurate than non-deadweight systems. Machines used to calibrate load cells vary from deadweight force standard machines or primary standards with the lowest overall uncertainty to single or multiple transducer machines with higher uncertainty. Some labs even use a universal testing machine or a homemade press to calibrate load cells. Deadweight machines are the most accurate because they are capable of calibrating ISO 376 Class 00, ASTM E74-18 Class AA verified range of forces, AS 2193 Class AA, and other force measuring devices requiring the utmost accuracy. Expanded uncertainty must be better than 50 ppm to assign a Class AA verified range of forces. This is easily achieved with the new 30,000 lbf deadweight machine, which has an expanded uncertainty of 20 ppm.
Morehouse has redesigned many of its automatic deadweight machines with conical lifters so the weights can be lowered by low-pressure air bladders to eliminate shock loading. The redesign also includes more room between weights and a rigid structure. Additionally, the weight complements are designed to eliminate unnecessary hysteresis errors, and weights do not have to be cycled off and on to achieve the necessary force points. The 30,000 lbf deadweight machine includes these design elements to assure the most accurate calibrations.
Morehouse Instrument Company: Since 1925, Morehouse has been committed to helping customers to lower measurement risk by lowering equipment uncertainties for force and torque. Today, Morehouse offers a wide range of force and torque calibration products, services, and training. In 2004, the company finished the construction of its new force calibration lab, which features a 120,000 lbf Morehouse Dead Weight Machine that achieves the best possible calibrations for customers and at a fraction of the cost other primary calibration labs charge. In 2010 Morehouse finished the construction of its primary torque calibration lab. The torque machine built by NPL gives Morehouse the privilege of being the second most accurate laboratory in the world for torque calibrations from 1 N-m through 2000 N-m (PTB has the lowest overall uncertainty). In 2020, despite a global pandemic, Morehouse finished adding a new 30,000 lbf deadweight machine to our calibration lab.