We introduce a simple thrust stand for the direct measurement of the millinewton impulses or thrusts delivered by small thrusters intended for in-space electric propulsion. The thruster under test, with a weight below 1.5 kg, is disposed on a horizontal platform and its impulse is measured as an overweight by using a strain gauge cell physically protected from the ambient plasma and vacuum conditions. This system provides ten thrust readings per second with noise peak to peak amplitudes of 0.10-0.18 mN. The calibration procedures to verify its dynamic response to time dependent thrusts in the range of 0-15 mN using control weights as well as its minimum thrust sensitivity δTs = 0.3 mN are discussed. Additionally, its simple conception permits a plain data reduction and analysis of steady state and low frequency thrust transients. This thrust stand was employed under low pressure and plasma ambient conditions to measure the steady impulses delivered by the Alternative Low Power Hybrid Ion Engine (ALPHIE) of 0.4-4.0 mN with absolute errors ΔT = ±0.3 mN. Finally, the experimental results show that a control electric voltage governs the ALPHIE thruster throttle.

中文翻译：

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基于单点称重传感器的推力支架，用于等离子推进器的脉冲测量

我们介绍了一个简单的推力支架，用于直接测量由用于空间电力推进的小型推进器提供的毫牛顿脉冲或推力。被测推进器的重量低于 1.5 kg，放置在水平平台上，通过使用应变计单元测量其脉冲超重，该应变计单元在物理上免受环境等离子体和真空条件的影响。该系统每秒提供十个推力读数，噪声峰峰值幅度为 0.10-0.18 mN。讨论了使用控制权重验证其对 0-15 mN 范围内的时间相关推力的动态响应及其最小推力灵敏度 δTs = 0.3 mN 的校准程序。此外，其简单的概念允许对稳态和低频推力瞬变进行简单的数据简化和分析。该推力支架在低压和等离子体环境条件下使用，以测量由替代低功率混合离子发动机 (ALPHIE) 提供的 0.4-4.0 mN 的稳定脉冲，绝对误差 ΔT = ±0.3 mN。最后，实验结果表明控制电压控制 ALPHIE 推进器油门。