Page - 1 Space Hardware Experiment Design ASEN4519 / 5519 Homework #3 Name: Due Date: 20/25 Nov. ‘03 Unique Identifier Note: You may have to make assumptions (and properly state those) to solve the problems (that’s life). Not all required information may be given. If in doubt, simplify with real life assumptions. This test is meant to be easy. Don’t hesitate to ask questions (303) 492-5875 or email ([email protected]) if you get stuck. Question 1 - Light: Show the sensitivity of the human eye as a function of wavelength. Show the difference to light used by plants for energy conversion. Indicate the ultraviolet and Infrared region. Which wavelength corresponds to blue, yellow, green, red light ? The peak intensity of sunlight on Earth is approximately at what wavelength ? 00.20.40.60.811.20 500 1000 1500wavelength [nm]EyePlant ____________________________________________________________________________ ________________________________________________________________ ________________________________________________________________ Question 2 - Data Acquisition: Given: 12 bit analog to digital converter (A/D), 16 single-ended or 8 differential channels, input range can be set by user to +5V (unipolar), ±5V (bipolar), +10V (unipolar) or ±10V (bipolar). You are using an IC temperature sensor LM335 with a signal of 10 mV/°C and an output offset of 2.73V at 0°C (i.e., 273K = 2.73V). The sensor will be used between 0°C and 100°C.Page - 2 1. What is the best input voltage setting for your A/D converter (+5V, ±5V, +10V, ±10V) using this sensor between 0 and 100°C and why ? Output at 0°C: _________________Volt Output at 100°C: _________________Volt Voltage range needed: _____________ for best resolution 2. at the setting of +5V (unipolar), what is the best resolution (both in mV and °C) that you can measure using the 12 bit A/D converter (resolution = capability to distinguish two voltages / temperatures from each other). (fill in table below) 3. What would the best resolution (°C and mV; see 2. above) be, if you had a) a 16 bit A/D, and b) if you had a 8 bit A/D converter, using the same LM335 sensor described in 1. (fill in table below) 4. You are considering using a different sensor, the LM34 (offset: 0°F = 0V, slope: 10 mV/°F). What is the best resolution (in °C) using the LM34 sensor with the 12 bit A/D converter at +5 V input range setting (unipolar). Given a choice, which sensor would you use for your experiment (to be measured: 0°C -> 100°C, as accurate as possible)? Why ? Output at 0°C: _________________Volt Output at 100°C: _________________Volt Voltage range needed: _____________ Resolution of LM34 _____________ °C / ‘step’ A/D set at +5V unipolar 8 bit 12 bit 16 bit Integer range (‘steps’) mV resolution at 0-5V range °C resolution using LM335 (10mV/°C) °C resolution using LM34 (10mV/°F) Alexander Hoehn Research Assistant Professor - Aerospace Engineering Sciences BioServe Space Technologies Campus Box 429 - Room ECAE 1B06 - Boulder CO 80303-0429 phone: (303) 492-5875 - fax: (303) 492-8883 email:
View Full Document
Unlocking...