12-09-2011, 10:18 AM
Hello Hort,
Liked the bullet list. Two thing to add would be vandelism and dust/dirt ingress (the other part of IP rating).
Section a), you could mention vandelism again and also UPS/power supplies. Electromagnetic radiation doesn't mean a lot to me. Use of the terms EMC or EMI is more widely understood and would gain extra marks if the student understands the difference between the two!
In section b) you raise an interesting point of how to evacuate heat but keep the IP rating. Don't stricly agree with the first sentence but agree with what you were trying to say. For me, although the points were valid, there was too much on the mitigation of possible site issues.
Train bourne equipment has just about the worst environment to live in. As PJW stated, axle-end tachos are notorious for failure due to mechanical wear, vibrations or being struck!
The conclusion is the attempt was good. It showed some insight but the answer should be limited to what the question is asking and answer it concisely, completely and explicitly. Keep going as I feel you are making great improvements with your technique.
Jerry
Liked the bullet list. Two thing to add would be vandelism and dust/dirt ingress (the other part of IP rating).
Section a), you could mention vandelism again and also UPS/power supplies. Electromagnetic radiation doesn't mean a lot to me. Use of the terms EMC or EMI is more widely understood and would gain extra marks if the student understands the difference between the two!
In section b) you raise an interesting point of how to evacuate heat but keep the IP rating. Don't stricly agree with the first sentence but agree with what you were trying to say. For me, although the points were valid, there was too much on the mitigation of possible site issues.
Train bourne equipment has just about the worst environment to live in. As PJW stated, axle-end tachos are notorious for failure due to mechanical wear, vibrations or being struck!
The conclusion is the attempt was good. It showed some insight but the answer should be limited to what the question is asking and answer it concisely, completely and explicitly. Keep going as I feel you are making great improvements with your technique.
Jerry
Le coureur