Balance Calibration Laboratory

Introduction

All ARA balances are calibrated in-house, and ARA offers a balance calibration service for customer supplied balances. Balances are calibrated to a very high standard using high accuracy dead-weight loadings. Non-standard balance installations can be accommodated with specialised loading adaptors.

ARA has decades of experience calibrating all types of wind tunnel balance - including main balances, panel balances and store balances.

All the balance calibration equipment is traceable to UK national standards.

Technical Information

Main balances are installed in the calibration frame which incorporates pitch and roll levelling mechanisms which compensate for any deflection under load.

A full set of pre-load checks are made including checks for hysteresis in the balance/sting joints.

During loading, deflection measurements of the support systems are recorded as standard and checks are continually made to ensure interference free operation of the live elements.

Facility Capabilities

• Standard equipment used to perform dead weight loadings in the calibration frame, which incorporates pitch and roll levelling mechanisms
• Non-standard balance set ups supplied with the necessary specialised loading adaptors.
• A balance calibration matrix produced from a full set of interactive calibrating load cycles, including first and second order interaction terms
• Checks against hysteresis in balance/sting joints
• Deflection measurements of support systems
• Checks to ensure interference free operation of live elements
• For a typical civil aircraft drag model balance, the achieved resolution of ±0.11N (±0.025lbf) in axial force components and ±0.60N (±0.135lbf) in normal force components in static calibration is equivalent to ∆C_A = 0.000014 and ∆C_N = 0.000075 for a typical qS of 8000N (1800lbf)