Wavelength-of-Light Compensation

Transcription

1 16 Wavelength-of-Light Compensation

2 Introduction Introduction This chapter provides the tables (tables 16-1 to 16-50) of Wavelength-of-Light (WOL) compensation values for different environmental conditions, and step-by-step instruction on how to calculate the compensation factor if your system operates in an environment other than those covered by the tables. Absolute Pressure Versus Barometric Pressure The ambient pressure used in determining your compensation factor must be absolute pressure, not the barometric " pressure (which is usually absolute pressure that has been corrected to sea level ). Barometric pressure, as defined, here, is the absolute pressure that would be measured at a given location, if that location was at sea level and the weather conditions were the same. Suppose, for example, that you were in Denver (Colorado, U.S.A.) at a time when the weather report said the barometric pressure was 762 mm (30.00 inches) of mercury. Since Denver's altitude is about 1.5 km (5000 feet), the absolute air pressure there and then would be closer to 635 mm (25 inches) of mercury. To measure pressure, you need an absolute pressure indicator, which is equivalent to a barometer that has not been corrected to sea level. When such a pressure indicator is not readily available, you can make a reasonable approximation to absolute pressure by reducing the barometric pressure obtained from the nearest weather station (at the local airport, for instance) by 2.5 mm (0.1 inch) of mercury of each 30 meters (100 feet) of altitude. That is P = P A B Altitude 30 x 2.5 P = P A B Altitude 100 x 0.1 For Metric Units For English Units where PA is the absolute pressure, and PB is the barometric pressure. Note that the altitude of the weather station is not considered here, since the number they report has already been corrected to sea level by the station User s Manual

3 Calculation of Exact Wavelength-of-Light (WOL) Compensation Factor Calculation of Exact Wavelength-of-Light (WOL) Compensation Factor If the Laser Position Transducer is being operated in an environment that is not included in the compensation factor tables in this manual, you can calculate the exact compensation factor to an accuracy of 0.1 ppm by using the following formulas. CAUTION The accuracy of your Laser Position Transducer is a function of your ability to provide it with the correct compensation factor for your measurement conditions. When determining the compensation factor by calculation rather than by using the compensation factor tables, the results you get depends on the resolution of the equipment on which you make your calculation and on your ability to operate it without error. You will be working with numbers that are very small and numbers that are very large; even the smallest error can have a significant effect on the accuracy of your answer, and any error is extremely difficult to detect or trace. We strongly suggest that you make a practice run, using values from any of the compensation factor tables, to get a feeling for what is required. In the formulas below T = Air Temperature P = Air Pressure H = Relative Humidity C = Compensation Factor, to be entered into the controller. C 10 6 = N + 10 where N is given in Metric and English systems by Metric: T in degrees Celsius, P in millimeters of mercury, H in % ( T) N = P H e T T English: T in degrees Fahrenheit, P in inches of mercury, H in % P( T) N = P H e T T User s Manual 16-3

4 Calculation of Exact Wavelength-of-Light (WOL) Compensation Factor EXAMPLE: Using the Standard conditions, Humidity = 50% = H Pressure (absolute) = 760 mm Hg = P Temperature = 20 C = T We will calculate the compensation factor, using the Metric formula for finding "N", and showing all our work T = (#1) (#1) = (#2) P x 10 6 (#2) = (#3) 1 + (#3) = (#4) (Save) T = (#5) 1 + (#5) = (#6) (#4)(#6) = (#7) P (#7) = (#8) (Save) e T = (#9) H x (#9) = (#10) x 10 3 (#10) = (#11) (Save) (#8) (#11) = (#12) (#12) = (#13) C = 6 10 (#13) = (#14) For comparison, the answer we were looking for in this example just happens to be User s Manual

5 Wavelength-of-Light (WOL) Compensation Tables This chapter contains tables of WOL compensation values for a variety of operating conditions. The tables are divided into two groups; the Metric group (Tables 16-1 through 16-25), and the English group (Tables through 16-50). Each group of tables (Metric or English is organized as follows: Table 16-1 and Table are wide-range charts, offering coarse compensation numbers for non precision measurements. Tables 16-2 through 16-25, and Tables through are more detailed charts, progressing from low to high altitudes, and from low to high temperature and humidity. To locate the appropriate table for your application, read the table heading for the percent humidity, pressure, and temperature range. The precise compensation number can be found where the temperature and pressure columns intersect. The compensation numbers in Tables 16-1 through represent the last four digits of a seven-digit fraction of the form 0.999abcd. The wavelength-of-light (WOL) compensation number is entered in the form 0.999abcd, where abcd is found in the tables. User s Manual 16-5

6 Table Metric Wide-Range (Temp = 2 to 50 C, Press = 525 to 800 mm, 50% Humidity) 16-6 User s Manual

7 Table Metric Low Alt, Low Temp, Low Humidity (Temp = 5 to 13 C, Press = 720 to 800 mm, 20% Humidity) User s Manual 16-7

8 Table Metric Low Alt, Low-Mid Temp, Low Humidity (Temp = 13.5 to 21.5 C, Press = 720 to 800 mm, 20% Humidity) 16-8 User s Manual

9 Table Metric Low Alt, Mid Temp, Low Humidity (Temp = 22 to 30 C, Press = 720 to 800 mm, 20% Humidity) User s Manual 16-9

10 Table Metric Low Alt, High-Mid Temp, Low Humidity (Temp = 30.5 to 38.5 C, Press = 720 to 800 mm, 20% Humidity) User s Manual

11 Table Metric High Alt, Low Temp, Low Humidity (Temp = 5 to 13 C, Press = 640 to 720 mm, 20% Humidity) User s Manual 16-11

12 Table Metric High Alt, Low-Mid Temp, Low Humidity (Temp = 13.5 to 21.5 C, Press = 640 to 720 mm, 20% Humidity) User s Manual

13 Table Metric High Alt, Mid Temp, Low Humidity (Temp = 22 to 30 C, Press = 640 to 720 mm, 20% Humidity) User s Manual 16-13

14 Table Metric High Alt, High-Mid Temp, Low Humidity (Temp = 30.5 to 38.5 C, Press = 640 to 720 mm, 20% Humidity) User s Manual

15 Table Metric Low Alt, Low Temp, Med Humidity (Temp = 5 to 13 C, Press = 720 to 800 mm, 50% Humidity) User s Manual 16-15

16 Table Metric Low Alt, Low-Mid Temp, Med Humidity (Temp = 13.5 to 21.5 C, Press = 720 to 800 mm, 50% Humidity) User s Manual

17 Table Metric Low Alt, Mid Temp, Med Humidity (Temp = 22 to 30 C, Press = 720 to 800 mm, 50% Humidity) User s Manual 16-17

18 Table Metric Low Alt, High-Mid Temp, Med Humidity (Temp = 30.5 to 38.5 C, Press = 720 to 800 mm, 50% Humidity) User s Manual

19 Table Metric High Alt, Low Temp, Med Humidity (Temp = 5 to 13 C, Press = 640 to 720 mm, 50% Humidity) User s Manual 16-19

20 Table Metric High Alt, Low-Mid Temp, Med Humidity (Temp = 13.5 to 21.5 C, Press = 640 to 720 mm, 50% Humidity) User s Manual

21 Table Metric High Alt, Mid Temp, Med Humidity (Temp = 22 to 30 C, Press = 640 to 720 mm, 50% Humidity) User s Manual 16-21

22 Table Metric High Alt, High-Mid Temp, Med Humidity (Temp = 30.5 to 38.5 C, Press = 640 to 720 mm, 50% Humidity) User s Manual

23 Table Metric Low Alt, Low Temp, High Humidity (Temp = 5 to 13 C, Press = 720 to 800 mm, 80% Humidity) User s Manual 16-23

24 Table Metric Low Alt, Low-Mid Temp, High Humidity (Temp = 13.5 to 21.5 C, Press = 720 to 800 mm, 80% Humidity) User s Manual

25 Table Metric Low Alt, Mid Temp, High Humidity (Temp = 22 to 30 C, Press = 720 to 800 mm, 80% Humidity) User s Manual 16-25

26 Table Metric Low Alt, High-Mid Temp, High Humidity (Temp = 30.5 to 38.5 C, Press = 720 to 800 mm, 80% Humidity) User s Manual

27 Table Metric High Alt, Low Temp, High Humidity (Temp = 5 to 13 C, Press = 640 to 720 mm, 80% Humidity) User s Manual 16-27

28 Table Metric High Alt, Low-Mid Temp, High Humidity (Temp = 13.5 to 21.5 C, Press = 640 to 720 mm, 80% Humidity) User s Manual

29 Table Metric High Alt, Mid Temp, High Humidity (Temp = 22 to 30 C, Press = 640 to 720 mm, 80% Humidity) User s Manual 16-29

30 Table Metric High Alt, High-Mid Temp, High Humidity (Temp = 30.5 to 38.5 C, Press = 640 to 720 mm, 80% Humidity) User s Manual

31 Table English Wide Range (Temp = 40 to 120 F, Press = 20 to 31 inches, 50% Humidity) User s Manual 16-31

32 Table English Low Alt, Low Temp, Low Humidity (Temp = 40 to 56 F, Press = 27 to 31 inches, 20% Humidity) User s Manual

33 Table English Low Alt, Low-Mid Temp, Low Humidity (Temp = 57 to 73 F, Press = 27 to 31 inches, 20% Humidity) User s Manual 16-33

34 Table English Low Alt, Mid Temp, Low Humidity (Temp = 74 to 90 F, Press = 27 to 31 inches, 20% Humidity) User s Manual

35 Table English Low Alt, High-Mid Temp, Low Humidity (Temp = 91 to 107 F, Press = 27 to 31 inches, 20% Humidity) User s Manual 16-35

36 Table English High Alt, Low Temp, Low Humidity (Temp = 40 to 56 F, Press = 23 to 27 inches, 20% Humidity) User s Manual

37 Table English High Alt, Low-Mid Temp, Low Humidity (Temp = 57 to 73 F, Press = 23 to 27 inches, 20% Humidity) User s Manual 16-37

38 Table English High Alt, Mid Temp, Low Humidity (Temp = 74 to 90 F, Press = 23 to 27 inches, 20% Humidity) User s Manual

39 Table English High Alt, High-Mid Temp, Low Humidity (Temp = 91 to 107 F, Press = 23 to 27 inches, 20% Humidity) User s Manual 16-39

40 Table English Low Alt, Low Temp, Med Humidity (Temp = 40 to 56 F, Press = 27 to 31 inches, 50% Humidity) User s Manual

41 Table English Low Alt, Low-Mid Temp, Med Humidity (Temp = 57 to 73 F, Press = 27 to 31 inches, 50% Humidity) User s Manual 16-41

42 Table English Low Alt, Mid Temp, Med Humidity (Temp = 74 to 90 F, Press = 27 to 31 inches, 50% Humidity) User s Manual

43 Table English Low Alt, High-Mid Temp, Med Humidity (Temp = 91 to 107 F, Press = 27 to 31 inches, 50% Humidity) User s Manual 16-43

44 Table English High Alt, Low Temp, Med Humidity (Temp = 40 to 56 F, Press = 23 to 27 inches, 50% Humidity) User s Manual

45 Table English High Alt, Low-Mid Temp, Med Humidity (Temp = 57 to 73 F, Press = 23 to 27 inches, 50% Humidity) User s Manual 16-45

46 Table English High Alt, Mid Temp, Med Humidity (Temp = 74 to 90 F, Press = 23 to 27 inches, 50% Humidity) User s Manual

47 Table English High Alt, High-Mid Temp, Med Humidity (Temp = 91 to 107 F, Press = 23 to 27 inches, 50% Humidity) User s Manual 16-47

48 Table English Low Alt, Low Temp, High Humidity (Temp = 40 to 56 F, Press = 27 to 31 inches, 80% Humidity) User s Manual

49 Table English Low Alt, Low-Mid Temp, High Humidity (Temp = 57 to 73 F, Press = 27 to 31 inches, 80% Humidity) User s Manual 16-49

50 Table English Low Alt, Mid Temp, High Humidity (Temp = 74 to 90 F, Press = 27 to 31 inches, 80% Humidity) User s Manual

51 Table English Low Alt, High-Mid Temp, High Humidity (Temp = 91 to 107 F, Press = 27 to 31 inches, 80% Humidity) User s Manual 16-51

52 Table English High Alt, Low Temp, High Humidity (Temp = 40 to 56 F, Press = 23 to 27 inches, 80% Humidity) User s Manual

53 Table English High Alt, Low-Mid Temp, High Humidity (Temp = 57 to 73 F, Press = 23 to 27 inches, 80% Humidity) User s Manual 16-53

54 Table English High Alt, Mid Temp, High Humidity (Temp = 74 to 90 F, Press = 23 to 27 inches, 80% Humidity) User s Manual

55 Table English High Alt, High-Mid Temp, High Humidity (Temp = 91 to 107 F, Press = 23 to 27 inches, 80% Humidity) User s Manual 16-55

56 Product specifications and descriptions in this document subject to change without notice. Copyright (C) 2002 Agilent Technologies Printed in U.S.A. 07/02 This is a chapter from the manual titled: Laser and Optics User's Manual For complete manual, order: Paper version: p/n CD version: p/n This chapter is p/n User s Manual