HATS-Y_im 电路图.pdf

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1、1 Introduction HATS-Y Series Chapter 1 INTRODUCTION and nominal) for all three decades is essentially the same, e.g. if the adjustment error at 100 k is 4 ppm, then it is also 4 ppm at 10 k and 1 M, remember- ing that the transfer accuracy error has to be added at these additional decade settings. T

2、he HATS-Y standards are constructed using matched low temperature coefficient, hermetically sealed resistors (except for 10 and 100 M step units) for high stability and imperviousness to moisture. Each resistance step is composed of multiple individual re- sistors for better power handling, heat dis

3、tribution, and higher voltage capability. In addition, there is a trim- ming network that allows precise setting of the resis- tance step values, and greatly simplifies subsequent calibrations. The switches are of special low-leakage construc- tion. Switches are placed at every junction and at the t

4、wo ends of the series string to connect that junction to either of the two binding posts; a center-off setting provides for no connection to that junction. By means of these switches, the resistances may be connected in various series-parallel combinations. Low-thermal-emf five way binding posts are

5、 used for connections to the two buses, and a shielded bnc con- nector provides for connection to one end of the re- sistor string. A third, metal, binding post provides a connection to the metal case; this may be used as a guard. The unit is housed in a contamination-and-moisture- resistant case Th

6、e insulation materials in the instru- ment are Kel-F plastic and teflon, for the highest pos- sible resistance and low moisture absorption. 1.1 General Description The HATS-Y Series (Figure 1.1) is a family of trans- fer standards suitable for making resistance calibra- tion transfer measurements fr

7、om 10 k to 1 G, with step sizes ranging from 100 k to 100 M In order to perform calibrations with a high degree of accuracy, reference standards must normally be em- ployed at every range or decade of the measuring or calibration instrumentation. Clearly this can be diffi- cult and costly, since the

8、se standards must be highly stable and their values must be known with a high degree of certainty and with a sufficient resolution. To minimize the cost and difficulty, a more practical means of performing such calibrations is to use trans- fer standards. The HATS-Y Series of transfer standard consi

9、sts of 11 matched equal value resistors, R, which may be connected in series or parallel combinations to pro- duce a number of values such as R/10, R, and 10R, thereby allowing progressive transfers to higher or lower decades. For lower resistance values (below 10 k) The HATS-LR Series of transfer s

10、tandards may by used. If one has a single primary standard with a traceable calibration, one can calibrate the transfer standard to the primary standard. The transfer standard may then be used at R/10, R, and at 10R, where R is the step size. It may be used at these three decades with an uncertainty

11、 that is equal to the initial calibration un- certainty of the steps plus the transfer uncertainty. For example, if a 100 k step HATS-Y unit has a nominal uncertainty of 5 ppm and a transfer uncer- tainty of 2 ppm, then it may be used at 10 k and 1 M with an uncertainty of 7 ppm. The nominal ad- jus

12、tment error (the difference between actual value RadioFans.CN 收音机爱 好者资料库 2 Specifications HATS-Y Series Chapter 2 SPECIFICATIONS For convenience to the user, the pertinent specifica- tions are given in an OPERATING GUIDE, Figure 2.1, affixed to the unit. A calibration chart, as shown in Figure 2.2,

13、is also affixed to the side of the unit. This gives the indi- vidual and progressive cumulative deviations from nominal. These are deviations which may be used for transfers. Specifications: Calibration Conditions: 23C, with meter guard applied to COM and ground applied to the center metal post, at

14、low power, traceable to SI. Initial cali- bration data is supplied with each instrument. Leakage Resistance: 10 T from terminal to case. Power Coefficient: 0.05 ppm/mW per resistor. Resistor Type: Matched low temperature coeffi- cient, hermetically sealed resistors, or high voltage film resistors fo

15、r 10 M and 100 M steps. In addi- tion, there is a lockable trimming potentiometer that Step Size100 k1 M10 M100 M Adjustment Accuracy 10 ppm 20 ppm 20 ppm 100 ppm Transfer Accuracy 2 ppm2 ppm2 ppm30 ppm Stability ppm/year 10 ppm 15 ppm 30 ppm 30 ppm Stability long term 30 ppm 30 ppm 50 ppm 50 ppm Te

16、mperature Coefficient 1 ppm/oC3 ppm/oC5 ppm/oC5 ppm/oC Matching Adj. Acc. 10 ppm 10 ppm 10 ppm 20 ppm TC 1 ppm3 ppm3 ppm5 ppm Calibration Uncertainty 5 ppm10 ppm 10 ppm 15 ppm allows precise setting of the resistance step values, and greatly simplifies subsequent calibrations. Switches: The switches

17、 are of special low-leakage construction. The switches are tied to every junction and at the two ends of the series string to connect that junction to either of the two binding posts; a cen- ter-off setting provides for no connection to that junc- tion. By means of these switches, the resistances ma

18、y be connected in various series-parallel combinations Terminals: Two low-thermal-emf five way binding posts; a shielded bnc connector provides for connec- tion to one end of the resistor string. A third metal binding post provides for connection to the metal case; this may be used as a guard. Dimen

19、sions: 35.6 cm W x 16.5 cm H x 10.2 cm D (14 x 6.5 x 4). Weight: 5 kg (11 lb.). Functional Schematic: RadioFans.CN 收音机爱 好者资料库 3 Specifications HATS-Y Series MODEL: HATS-Y-100M SN: E1-0536109 Transfer Accuracy: Limited only by short term repeatability of resistance values. Calibration Conditions: 23C

20、, with meter guard applied to COM and ground applied to G, at low power, traceable to SI. Calibration data supplied with instrument. Power Coefficient: 10 T from terminal to case. Operation: (With switch 0 being leftmost). To set standard to R/10, set Switch 0 down, Switch 1 up, switch 2 down and so

21、 on; Switch 11 off. To set standard to 10R, set Switch 0 down, Switch 10 up, all other switches off. HATS-Y OPERATING GUIDE To set standard to 1R, set Switches 0 and 6 down, Switches 3 and 9 up, all other switches off. Functional Schematic: IET LABS, INC.IET LABS, INC.IET LABS, INC.IET LABS, INC.IET

22、 LABS, INC. Westbury, NY 11590 (516) 334-5959 (800) 899-8438 HATS-YLBL (PPM style)/ 4-4-06 Step Size100 k1 M10 M100 M Adjustment Accuracy 10 ppm 20 ppm 20 ppm 100 ppm Transfer Accuracy 2 ppm2 ppm2 ppm30 ppm Stability ppm/year 10 ppm 15 ppm 20 ppm 30 ppm Stability long term 30 ppm 30 ppm 30 ppm 50 pp

23、m Temperature Coefficient 1 ppm/oC 3 ppm/oC 5 ppm/oC 5 ppm/oC Matching Adj. Acc. 10 ppm 10 ppm 10 ppm 20 ppm TC 1 ppm3 ppm3 ppm5 ppm Calibration Uncertainty 5 ppm10 ppm 10 ppm 15 ppm Figure 2.1. Typical OPERATING GUIDE Affixed to Unit Figure 2.2. Typical Calibration Chart, providing deviations, Affi

24、xed to Unit CALIBRATION CHART Deviations from 10 M Nominal Traceable to SI Temperature: 23.1C Date: 29 Mar 2006 Date Due: 29 Mar 2007 Model: HATS-Y-10M Serial Number: E1-0536108 BY: JOS 516-334-5959 (FAX) 516-334-5988 IET LABS, INC.IET LABS, INC.IET LABS, INC.IET LABS, INC.IET LABS, INC.Westbury, NY

25、 11590 Cumulative (ppm) 3.8 4.6 2.4 2.0 1.7 1.9 1.6 2.0 1.9 1.9 2.3 Individual (ppm) 3.8 5.5 1.1 0.9 0.6 2.7 0.2 4.6 0.7 2.5 6.5 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 RadioFans.CN 收音机爱 好者资料库 4 Installation HATS-Y Series Chapter 3 INSTALLATION 3.1 Initial Inspection IET instruments receive a careful mec

26、hanical and electrical inspection before shipment. Upon receipt, verify that the contents are intact and as ordered. The instrument should then be given a visual and op- erational inspection. If any shipping damage is found, contact the carrier and IET Labs. If any operational problems are en- count

27、ered, contact IET Labs and refer to the war- ranty at the beginning of this manual. Save all original packing material for convenience in case shipping of the instrument should become nec- essary. 3.2 Installation For a rack mounted model, installation on a 19 inch rack may be made using the slots i

28、n the rack mount- ing ears. A mounting location that does not expose the unit to excessive heat is recommended. For bench models, no installation as such is required, because this instrument series is not powered. Since it is a high-accuracy instrument, it is recommended that a bench space be provid

29、ed that would not ex- pose it to abuse and keep it protected from tempera- ture extremes and contaminants. 3.3 Repackaging for Shipment If the instrument is to be returned to IET Labs, con- tact the Service Department at the number or ad- dress, shown on the front cover of this manual, to obtain a R

30、eturned Material Authorization (RMA) number and any special shipping instructions or as- sistance. Proceed as follows: 1. Attach a tag to the instrument identifying the owner and indicate the service or repair to be accomplished. Include the model number, the full serial number of the instrument, th

31、e RMA number, and shipping ad- dress. 2. Wrap the instrument in heavy paper or plastic. 3. Protect the front panel and any other protrusions with cardboard or foam padding. 4. Place instrument in original container or equally substantial heavy carton. 5. Use packing material around all sides of inst

32、ru- ment. 6. Seal with strong tape or strapping. 7. Mark shipping container DELICATE INSTRU- MENT, FRAGILE, etc. 3.4 Storage If this instrument is to be stored for any extended period of time, it should be sealed in plastic and stored in a dry location. It should not be exposed to tem- peratures bel

33、ow -10oC or above +50oC. Extended exposure to temperature extremes can result in an irreversible change in resistance and would require recalibration. 5 Operation HATS-Y Series Chapter 4 OPERATION 4.1 Initial Inspection and Setup This instrument was carefully inspected before ship- ment. It should b

34、e in proper electrical and mechanical operating order upon receipt. An OPERATING GUIDE and a CALIBRATION CHART are attached to the case of the instrument to provide ready reference to specifications. 4.2 Setting for Various Resistance Combinations The HATS-Y Series Transfer Standard, may be set into

35、 any number of parallel and/or series combina- tions to produce different resulting net resistances. Note the 12 switches located at the junctions of the 11 resistors as represented on the front panel. The center or OFF position is straight ahead with the switch set to the unconnected dot. The switc

36、h may me set, as shown, to connect to the A or B binding posts. For resistance applications, connect to the A and B binding posts. A guard shield may be connected to the metal center binding post. Set the switches as desired to obtain the desired re- sistance between the A and B binding posts. For e

37、x- ample, set the lowest (left bank) switch to A; this con- nects the lower end of R1 to the A binding post. Then set the next the (right bank) switch to B; this con- nects the upper end of R1 to the B binding post. Thus, we now have R1 connected between the A and B binding posts for an effective va

38、lue of 1R, where R is the step size. For 2 R, Set the lowest switch to A as before, and set the 3rd switch (left bank) to B. Thus the unit may be set to yield resistance settings from 1R to 11R. Note that the location of the switches on the “left bank” or the “right bank” has no significance. Any of

39、 the 12 switches may be set to either the A or B binding posts. See Figure 4.1 for various switch configurations to get series-parallel combinations resulting in com- posite resistance values of R/10, 1R, and 10R. These values are very useful in calibrating resis- tance values having one tenth to te

40、n times the step value. Note that the 1R value should be obtained with 9 resistors, as shown in Figure 4.1c, and not with one resistor. This offers the advantage of using the combined value of nine resistors, and allows the use of the same adjustment error The deviations of each individual resistor

41、from its nominal value, as well as the cumulative average de- viation of the resistance string is given in a CALI- BRATION CHART attached to the unit. Figure 2.2 shows a typical chart. Figure 4.2 may be reproduced to record later calibrations and to affix to the unit. What is important to note is th

42、at any series, parallel, or series-parallel configuration results in the net de- viation being essentially equal to the average devia- tion for that group of resistors regardless of how they are connected, as long as the power applied is di- vided equally, (or almost equally) among the resis- tors.

43、This is clearly the case with the R/10 and the 10R configurations, i.e. that they have they have the same deviations. It is also true with the 9 resistor series-parallel configuration, since the effect of the deviation of the single missing resistor may be safely neglected. This property is very use

44、ful since it per- mits making accurate transfers across three decades with one single unit. 6 Operation HATS-Y Series A single high accuracy, high stability standard whose value is traceable to SI may thus be transferred to other values using the HATS-Y Series in various com- binations. Example: For

45、 example, a 10 k standard may be compared with a HATS-Y unit with 100 k steps connected in parallel, as described above, to provide a 10 k re- sistance. Once a comparison is made, a net devia- tion of the parallel R/10 combination is obtained. This average or net deviation remains constant for all c

46、ombination, and therefore the standard is effectively transferred with the same deviation plus the trans- fer accuracy of the unit to another decade, 10R or 1 M in this example. It may also be transferred to the single step R value with the series parallel combi- nation. See Figure 4.1. This process

47、 may be continued with another transfer standard, 10 M steps in this example, which would first be configured in the R/10 mode to produce 1 M to start, and then 10 M and 100 M with the same deviation. The transfer uncertainty as speci- fied, must, of course, be added at each transfer. 4.2 Use as a S

48、tand-Alone Standard Whenever an application requires a resistance stan- dard that has an accuracy that is met by the initial or long term accuracies of the HATS-Y Series, as speci- fied, the HATS-Y unit may be used as a calibration source at any value desired. For example, the HATS- Y-100 k step uni

49、t may be used as a calibration source with an adjustment accuracy of 10 ppm and a stability of 20 ppm/year. 4.3 Use as a Precision Voltage Divider For voltage ratio applications, See Figure 4.3. Con- nect the input voltage low to bnc connector and the high to the B binding post. The “tap,” or ratio voltage is obtained from the A binding post. 4.4 General Considerations for best performance Since the HATS-Y is a precision high resistance unit, any electrical leakage across the terminals will affect performance, especially with higher resistance step models. It is recomm