Magnetorquer Test Plan

Introduction

This test has been adapted from the test procedures created by York University for the Iris mission.

Test Description: This test will measure the magnetorquers power draw and generated magnetic dipole to verify required performance.

Completed: 

Documented by: Riley Sweeney

Resources Required:

• Tools: Digital calipers, pen/marker, masking tape

• Hardware and Equipment: Magnetorquer, power supply, magnetometer (ideally calibrated)

• PPE: Please use ESD bracelet and mat wherever possible when handling electronic equipment.

Verification Activities: R-ARC-ADC-003-4791, R-ARC-ADC-075-5562, 

Pass Criteria: 

Test Apparatus

Ideally, this test should be performed inside a Helmholtz cage to minimize variability between trials. If a Helmholtz cage is not used, it is recommended to perform more trials to reduce the affect of small changes in the local magnetic field on test results.

Test Set-Up

1. The first step is to prepare your flat desk space and make sure that no metal or electronical items are in the immediate vicinity. 

2. Put tape over the area in a cross formation. Make sure the lines of the cross are as perpendicular as possible. This is done so that the distance from the magnetorquers center to each point is known. 

3. Mark the different points that you would like the measurement to be taken at down the measurement axes. The two different lines in the cross should represent the different axes being looked at. 

4. Prepare the table below for each of the different plane configurations, as shown in the background information section both the x- and y-axis of the magnetorquer are symmetrical allowing for only one of the x-z and y-z planes to be tested. 

5. If you are using a zeroing chamber for the magnetometer, the next step is the zero the magnetometer. This is done by putting it in the zeroing chamber then hitting the zero button. *NOTE* the magnetometer might not be perfectly calibrated after the zero. To correct for this, keep the magnetometer in the zeroing chamber and record the offset. *NOTE* Keep the zeroing chamber as far away from the magnetorquer as possible as the magnetic field can cause interference. 

Test Procedures

1. If you are using a power source connect the magnetorquer to the power source. For the first round off measurements, leave the magnetorquer unpowered.  *NOTE* the magnetorquers can handle a maximum of 0.2 W of power at 5 V. The current MUST NOT exceed 0.04 A at 5 V or the magnetorquer may be damaged. If you are using a MCU, connect the magnetorquer to the 5 V and GND line and a simple code controlling the voltage should be used. 

2. Start taking measurements with the magnetometer at the different measurements points which were marked previously. Record results in the results table below.

3. Once all the measurements are taken, the magnetometer should be zeroed and the previous steps repeated for each round of measurements. Repeat as much as the confidence level required, at least two are recommended. 

4. After the first batch of results is recorded, the magnetorquer is powered to 0.01 W. Allow a few seconds for it to charge up fully.

5. Repeat the measurement process with the magnetometer with different levels of power supplied to see the dipole response vs power supplied. This test recommends 0.01, 0.1, and 0.2 W.

6. After all the measurements for one geometry have been taken, rotate the magnetorquer into a new geometry and repeat the measurements. This is done until all of the unique geometries for the magnetorquer have been rotated through. 

7. Repeat these steps for each unique magnetorquer. 

Data Analysis

Provide step-by-step instructions for data analysis, including location of data storage.

1)     Step 1

2)     Step 2

3)     Step 3

a)     Sub-step a

b)     Sub-step b