Calcert
User Manual for IET LABS models including: HARS-X, HARS-X High Accuracy Resistance Substituter, High Accuracy Resistance Substituter, Accuracy Resistance Substituter, Resistance Substituter, Substituter
File Info : application/pdf, 15 Pages, 474.14KB
DocumentDocumentPRECISION INSTRUMENTS FOR TEST AND MEASUREMENT HARS-X and X2 High Accuracy Resistance Substituter User and Service Manual Copyright © 2018 IET Labs, Inc. HARS-X im/October 2018 IET LABS, INC. 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com sales@calcert.com IET LABS, INC. 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com sales@calcert.com HARS-X WARRANTY We warrant that this product is free from defects in material and workmanship and, when properly used, will perform in accordance with applicable IET specifications. If within one year after original shipment, it is found not to meet this standard, it will be repaired or, at the option of IET, replaced at no charge when returned to IET. Changes in this product not approved by IET or application of voltages or currents greater than those allowed by the specifications shall void this warranty. IET shall not be liable for any indirect, special, or consequential damages, even if notice has been given to the possibility of such damages. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. Table of Contents 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com i sales@calcert.com HARS-X and X2 WARNING OBSERVE ALL SAFETY RULES WHEN WORKING WITH HIGH VOLTAGES OR LINE VOLTAGES. Dangerous voltages may be present inside this instrument. Do not open the case Refer servicing to qualified personnel HIGH VOLTAGES MAY BE PRESENT AT THE TERMINALS OF THIS INSTRUMENT WHENEVER HAZARDOUS VOLTAGES (> 45 V) ARE USED, TAKE ALL MEASURES TO AVOID ACCIDENTAL CONTACT WITH ANY LIVE COMPONENTS. USE MAXIMUM INSULATION AND MINIMIZE THE USE OF BARE CONDUCTORS WHEN USING THIS INSTRUMENT. Use extreme caution when working with bare conductors or bus bars. WHEN WORKING WITH HIGH VOLTAGES, POST WARNING SIGNS AND KEEP UNREQUIRED PERSONNEL SAFELY AWAY. CAUTION DO NOT APPLY ANY VOLTAGES OR CURRENTS TO THE TERMINALS OF THIS INSTRUMENT IN EXCESS OF THE MAXIMUM LIMITS INDICATED ON THE FRONT PANEL OR THE OPERATING GUIDE LABEL. ii 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com sales@calcert.com Contents Chapter 1: Introduction 1.1 Introduction..................................................................................1 Chapter 2: Specifications Specifications .....................................................................................2 Ordering Information .........................................................................3 Chapter 3: Operation 3.1 Initial Inspection and Setup .........................................................5 3.2 Connection ...................................................................................5 3.2.1 General Considerations......................................................5 3.2.3 Four-Wire Kelvin Lead Connections.................................5 3.2.4 Thermal emf Considerations..............................................6 3.3 Dial Setting ..................................................................................6 3.4 Environmental Conditions ..........................................................6 Chapter 4: Maintenance 4.1 Verification of Performance .........................................................7 4.1.1 Calibration Interval ............................................................7 4.1.2 General Considerations......................................................7 4.1.3 Calibration Procedure ........................................................7 4.2 Schematic .....................................................................................8 4.3 Replaceable Parts List..................................................................9 HARS-X Table of Contents 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com iii sales@calcert.com HARS-X Figures and Tables Figure 1-1. HARS-X Series High Accuracy Resistance Substituter ..........1 Figure 1-2. Single-Decade HARS Unit .....................................................1 Figure 2-1. Typical Operating Guide Affixed to Unit ...............................4 Figure 3-1 Optimal 4-Wire Kelvin Lead Connection ................................6 Figure 4-1. HARS Series Schematic Diagram ..........................................8 Table 4-2: Replacement List......................................................................9 Figure 4-2. HARS-X Replaceable Parts....................................................9 iv 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com Table of Contents sales@calcert.com HARS-X and X2 Chapter 1 INTRODUCTION 1.1 Introduction The High-Accuracy Resistance Substituter (HARS) series of resistance decade substituters is a family of instruments providing a very broad choice of highperformance resistance sources. Any number of decades from one to eleven is available in a choice of accuracies. See Figures 1-1 and 1-2. The HARS substituter is a precision resistance source with excellent characteristics of stability, temperature coefficient, power coefficient, and frequency response. The HARS Series employs very-low-resistance switches with silver-alloy contacts. A special design keeps zero resistance to less than 1 m per decade. Self cleaning keeps the silver contacts from becoming tarnished when unused, or when only low currents are passed through them. This is most often the case when only minute test currents are drawn by digital multimeters or other test instruments. Contact resistance is stable and remains low and repeatable. High-quality gold-plated tellurium-copper binding posts serve to minimize the thermal emf effects which would artificially reflect a change in dc resistance measurements. All other conductors within the instrument, as well as the solder employed, contain no metals or junctions that could contribute to thermal emf problems. The standard models offer a choice of one through eleven decades. The panels are clearly labeled showing the step size and maximum voltage and current limitations for each decade. With a resolution as low as 1 m and a maximum available resistance of over 111 M, the HARS series may be used for exacting precision measurement applications requiring high accuracy, good stability, and low zero-resistance. They can be used as components of dc and ac bridges, for calibration, as transfer standards, and as RTD simulators. Single-decade units may be panel-mounted and combined with additional units to form potentiometer circuits or other configurations. The larger units may be rack-mounted to serve as components in measurement and control systems. Figure 1-1. HARS Series High Accuracy Resistance Substituter Figure 1-2. Single-Decade HARS Unit. Introduction 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com 1 sales@calcert.com HARS-X and X2 Chapter 2 SPECIFICATIONS For convenience to the user, the pertinent specifications are given in an OPERATING GUIDE affixed to the case of the instrument. Figure 2.1 shows a typical example. SPECIFICATIONS Resistance per step Total decade resistance Stability (±ppm/yr) Long-term stability (±ppm/3 yrs) Temperature coefficient (±ppm/°C) Resistor type 1 m 10 m 50 75 10 m 100 m 50 75 100 m 1 50 75 1 10 20 25 10 100 20 25 100 1 k 20 25 1 k 10 k 20 25 10 k 100 k 20 25 100 k 1 M 20 25 1 M 10 M 20 25 10 M 100 M 50 100 50 20 Resistance wire 20 20 15 5 5 Wirewound, non-inductive 5 5 5 10 Metal oxide film *Subject to maximum of 2000 V to case Max current 8.0 A 4.0 A 1.6 A 0.8 A 0.25 A 80 mA 23 mA 7 mA 2.3 mA* 0.7 mA* 0.1 mA* HARS-X Max voltage (per step) 5 mV Max power (per step) 0.04 W 40 mV 0.16 W 0.16 V 0.25 W 0.8 V 0.6 W 2.5 V 0.6 W 8 V 0.6 W 23 V 0.5 W 70 V 0.5 W 230 V* 0.5 W* 700 V* 0.5 W* 1000 V* 0.1 W* Max current 9.0 A 6.3 A 2.2 A 1.1 A 0.35 A 110 mA 35 mA 11 mA 3 mA* 1 mA* 0.1 mA* HARS-X2 Max voltage (per step) Max power (per step) 9 mV 0.08 W 63 mV 0.4 W 0.3 V 0.5 W 1.1 V 1.2 W 3.5 V 1.2 W 11 V 1.2 W 35 V 1.2 W 110 V 1.2 W 500 V* 1 W* 1000 V* 1 W* 1000 V* 0.1 W* Accuracy: 1 M steps: ±(0.01% + 2 m) 10 M steps: ±0.03% After subtraction of zero-resistance, at 23°C; traceable to SI Zero resistance: 1 M steps: 1 m per decade 10 M steps: 3 m Switch type: Multiple solid silver alloy contacts, continuous rotation Switch capacitance: <1 pF between contacts Operation: If switches have not been operated for an extended period of time, they should be rotated a few times in both directions to restore contact resistance to specifications. Environmental conditions: Operating conditions: +10 to +40°C, <80% RH Storage conditions: -20 to +65°C Terminals: 3 Low-thermal-emf tellurium-copper binding posts with standard 3/4 inch spacing, plus shield terminal; connections on the rear of the instrument are available (RO option). -K Option: Kelvin connection is available as an option with 5 binding posts 2 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com Specifications sales@calcert.com HARS-X and X2 ORDERING INFORMATION Model* HARS-X-1-0.001 HARS-X-1-0.01 HARS-X-1-0.1 HARS-X-1-1 HARS-X-1-10 HARS-X-1-100 HARS-X-1-1K HARS-X-1-10K HARS-X-1-100K HARS-X-1-1M HARS-X-1-10M HARS-X-2-0.001 HARS-X-2-0.01 HARS-X-2-0.1 HARS-X-2-1 HARS-X-2-10 HARS-X-2-100 HARS-X-2-1K HARS-X-2-10K HARS-X-2-100K HARS-X-2-1M HARS-X-3-0.001 HARS-X-3-0.01 HARS-X-3-0.1 HARS-X-3-1 HARS-X-3-10 HARS-X-3-100 HARS-X-3-1K HARS-X-3-10K HARS-X-3-100K Total resistance () 0.01 0.1 1 10 100 1 k 10 k 100 k 1 M 10 M 100 M 0.11 1.1 11 110 1.1 k 11 k 110 k 1.1 M 11 M 110 M 1.11 11.1 111 1.11 k 11.1 k 111 k 1.11 M 11.1 M 111 M No of Dials 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 Resolution () 0.001 0.01 0.1 1 10 100 1 k 10 k 100 k 1 M 10 M 0.001 0.01 0.1 1 10 100 1 k 10 k 100 k 1 M 0.001 0.01 0.1 1 10 100 1 k 10 k 100 k Mechanical: Model Dimensions 1 decade 7.7 cm W x 7.7 cm H x 8.4 cm D (3" x 3" x 3.3") 31 cm W x 8.9 cm H x 10.2 cm D 2-3 decade (12.2" x 3.5" x 4") 37.5 cm W x 8.9 cm H x 10.2 cm D 4-5 decade (14.75" x 3.5" x 4") 6 decades 43.9 cm W x 8.9 cm H x 10.2 cm D 7 decades (17.3" x 3.5" x 4") 8 decades 9 decades 48.3 cm W x 17.8 cm H x 17.8 cm D 10 decades (19" x 7" x 7") 11 decades Weight 0.45 kg (1 lb) 1.7 kg (3.8 lb) 2.0 kg (4.3 lb) 2.2 kg (4.8 lb) 2.4 kg (5.3 lb) 3.4 kg (7.5 lb) 3.5 kg (7.7 lb) 3.6 kg (7.9 lb) 3.7 kg (8.1 lb) Model* HARS-X-4-0.001 Total resistance () 11.11 HARS-X-4-0.01 111.1 HARS-X-4-0.1 1.111 k HARS-X-4-1 11.11 k HARS-X-4-10 111.1 k HARS-X-4-100 1.111 M HARS-X-4-1K 11.11 M HARS-X-4-10K 111.1 M HARS-X-5-0.001 111.11 HARS-X-5-0.01 1.1111 k HARS-X-5-0.1 11.111 k HARS-X-5-1 111.11 k HARS-X-5-10 1.1111 M HARS-X-5-100 11.111 M HARS-X-5-1K 111.11 M HARS-X-6-0.001 1.111 11 k HARS-X-6-0.01 11.1111 k HARS-X-6-0.1 111.111 k HARS-X-6-1 1.111 11 M HARS-X-6-10 11.1111 M HARS-X-6-100 111.111 M HARS-X-7-0.001 11.111 11 k HARS-X-7-0.01 111.1111 k HARS-X-7-0.1 1.111 111 M HARS-X-7-1 11.111 11 M HARS-X-7-10 111.1111 M HARS-X-8-0.001 111.111 11 k HARS-X-8-0.01 1.111 111 1 M HARS-X-8-0.1 11.111 111 M HARS-X-8-1 111.111 11 M HARS-X-9-0.001 1.111 111 11 M HARS-X-9-0.01 11.111 111 1 M HARS-X-9-0.1 111.111 111 M HARS-X-10-0.001 11.111 111 11 M HARS-X-10-0.01 111.111 111 1 M HARS-X-11-0.001 111.111 111 11 M * Use "X2" for higher power model No of Dials 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 6 6 6 6 6 6 7 7 7 7 7 8 8 8 8 9 9 9 10 10 11 Resolution () 0.001 0.01 0.1 1 10 100 1 k 10 k 0.001 0.01 0.1 1 10 100 1 k 0.001 0.01 0.1 1 10 100 0.001 0.01 0.1 1 10 0.001 0.01 0.1 1 0.001 0.01 0.1 0.001 0.01 0.001 OPTIONS - RM Rack mountable case for standard 19" rack - K Kelvin type 4-terminal binding posts - RO Rear output binding posts Specifications 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com 3 sales@calcert.com Specifications sales@calcert.com www.calcert.com HARS-X SERIES HIGH ACCURACY DECADE RESISTANCE SUBSTITUTER CONSULT INSTRUCTION MANUAL FOR PROPER INSTRUMENT OPERATION Resistance per step Total deacde resistance Max current Max Power voltage per/step (W) 1 m 10 m 8 A 5 mV 0.4 10 m 100 m 4 A 40 mV 0.16 100 m 1 1.6 A 0.16 V 0.25 1 10 .8 A 0.8 V 0.6 10 100 .25 A 2.5 V 0.6 100 1 k 80 mA 8 V 0.6 1 k 10 k 23 mA 23 V 0.5 10 k 100 k 7 mA 70 V 0.5 100 k 1 M 2.3 mA* 230 V* 0.5* 1 M 10 M 0.7 mA* 700 V* 0.5* 10 M 100 M 0.1 mA* 1000 V* 0.1* *Subject to maximum of 2000 V to case Stability (±ppm/yr) 50 50 50 20 20 20 20 20 20 20 50 Long-term stability (±ppm/3 yrs) 75 75 75 25 25 25 25 25 25 25 100 Temp. coeffieient (±ppm/°C) 50 20 20 20 15 5 5 5 5 10 10 Resistor type Resistance Wire Wirewound, non-inductive Metal oxide film Accuracy: 1 M steps: ±(0.01% + 2 m) 10 M steps: ±0.03% After subtraction of zero resistance, at 23°C; traceable to SI Zero Resistance: 1 M steps: 1 m per decade 10 M steps: approx. 3 m Switch Type: Multiple solid silver alloy contacts, continuous rotation Switch Capacitance: <1 pF between contacts Operating Conditions: +10 to + 40°C, <80% RH Operation: If switches have not been operated for an extended period, they should be rotated a few times to restore contact resistance to specifications. WARNING MODEL: HARS-X-6-0.01 SN: C3-09404334 Observe all safety rules when working with high voltages or line voltages. Connect the (G) terminal to earth ground in order to maintain the case at a safe voltage. Whenever hazardous voltages (>45 V) are used, take all measures to avoid accidental contact with any live components: a) Use maximum insulation and minimize the use of bare conductors. b) Remove power when adjusting switches. c) Post warning signs and keep personnel safely away. IET LABS, INC. · 534 Main Street, Westbury, NY 11590 · (800) 899-8438 · (516) 334-5959 · Fax: (516) 334-5988 CAGE CODE: 62015 www.ietlabs.com HARSXCLBL/p1/HARS-X gen'l/55%/03-02-2010 25 30 20 15 0 10 5 4 1.888.610.7664 Figure 2-1. Typical Operating Guide Affixed to Unit HARS-X and X2 HARS-X and X2 Chapter 3 OPERATION 3.1 Initial Inspection and Setup 3.2.2 Electrical Considerations This instrument was carefully inspected before shipment. It should be in proper electrical and mechanical order upon receipt. An OPERATING GUIDE is attached to the case of the instrument to provide ready reference to specifications. 3.2 Connection 3.2.1 General Considerations The HARS Series Decade unit provides three terminals labeled H (high), L (low), and G (ground). The H and L terminals are connected to the ends of the resistance being set; the G terminal is connected to the case. The G terminal may be used as a guard or shield terminal. It may also be connected (using a shorting link) to the L terminal to allow two-terminal as opposed to three-terminal measurements. In order to make the most stable measurements, determine which is the more sensitive of the two user leads, i.e. the one going into a higher impedance. This lead should be connected to the more protected one of the two HARS terminals. That would either be the HARS terminal that is shorted to the case, or the LOW HARS terminal whenever neither is connected to the case. If switches have not been operated for an extended period, they should be rotated a few times to restore contact resistance to specifications. In order to make proper use of the full performance capabilities of the HARS unit, especially if low resistance or low-resistance increments are important, take care when connecting to the terminals of the decade box. In particular, in order to keep contact resistance to a minimum, take the most substantial and secure connection to the binding posts. They accept banana plugs, telephone tips, spade lugs, alligator clips, and bare wire. The largest or heaviest mating connection should be made, and, where applicable, the binding posts should be securely tightened. These considerations may be relaxed whenever single milliohms are considered insignificant for the task being performed. 3.2.3 Four-Wire Kelvin Lead Connections Whenever possible, 4-wire Kelvin leads, the ideal connection, should be employed. Such a connection minimizes the effects of contact resistance and approaches ideal performance. If the four terminals are available as clamps similar to alligator clips, they may be connected to the necks of the binding posts. If the four terminals are available separately, the optimal connection is shown in Figure 3.1, where the current leads are introduced into the top of the binding posts, and the voltage leads at the necks. Operation 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com 5 sales@calcert.com HARS-X and X2 Figure 3-1 Optimal 4-Wire Kelvin Lead Connection To determine the resistance obtained when one or more "10" settings are used, simply add "1" to the next higher decade. For example, a setting of 3-610-0-10 becomes: 3 30 0 0 0 6 6 0 0 0 10 1 0 0 0 0 0 0 10 1 0 ____________________________ TOT 37 0 1 0 3.2.4 Thermal emf Considerations The highest-quality low-emf components are used in the HARS Series. There nevertheless may be some minute thermal emf generated at the test leads where they contact the gold-plated binding posts. This emf will not reflect itself if an ac measurement instrument is employed. It will also be eliminated if a meter with a "True Ohm" capability is used. Otherwise it may represent itself as a false component of the dc resistance measurement. It is also possible to take a second measurement with the leads reversed and average the reading. 3.3 Dial Setting Whenever the dials are used in positions 0-9, the resulting resistance is read directly. Both the decimal point and the steps are clearly marked on the panel. For additional flexibility and range, each decade provides a "10" position setting. This "10" position on any one decade equals the "1" position on the next higher decade. It adds about 11% to the nominal total decade resistance. and a setting of 10-10-10-l0-10.10 becomes: 10 1 0 0 0 0 0.0 10 1 0 0 0 0.0 10 1 0 0 0.0 10 1 0 0.0 10 1 0.0 .10 1.0 ____________________________ TOT 1 1 1 1 1 1.0 3.4 Environmental Conditions For optimal accuracy, the decade box should be used in an environment of 23oC. It should be allowed to stabilize at that temperature after any significant temperature variation. Humidity should be maintained at laboratory conditions. This is especially important if high resistances are involved. 6 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com Operation sales@calcert.com HARS-X and X2 Chapter 4 MAINTENANCE 4.1 Verification of Performance 4.1.1 Calibration Interval The HARS Series instruments should be verified for performance at a calibration interval of twelve (12) months. This procedure may be carried out by the user if a calibration capability is available, by IET Labs, or by a certified calibration laboratory. If the user should choose to perform this procedure, then the considerations below should be observed. 4.1.2 General Considerations It is important, whenever testing the HARS Series Decade Units, to be very aware of the capabilities and limitations of the test instruments used. A resistance bridge may be employed, and there are direct-reading resistance meters or digital multimeters available that can verify the accuracy of these units, especially when used in conjunction with standards that can serve to confirm or improve the accuracy of the testing instrument Such test instruments must be significantly more accurate than ±(l00ppm+2 m) for all applicable ranges, allowing for a band of uncertainty of the instrument itself. A number of commercial bridges and meters exist that can perform this task; consult IET Labs. It is important to allow both the testing instrument and the HARS Substituter to stabilize for a number of hours at the nominal operating temperature of 23OC, and at nominal laboratory conditions of humidity. There should be no temperature gradients across the unit under test. Substantial Kelvin-type 4-wire test terminals should be used to obtain accurate low-resistance readings. It is convenient, once the zero resistance has been determined, to subtract it from the remaining measurements. This can be automatically done in many instruments which have an offset subtraction capability. 4.1.3 Calibration Procedure 1. Confirm the zero resistance of the unit. 2. Determine the allowable upper and lower limits for each resistance setting of each decade based on the specified accuracy. For the HARS series, these limits for any resistance "R" are [R±(0.0001 R + 2 m)]. 3. Confirm that the resistances fall within these limits after subtraction of the zero resistance. 4. If any resistances fall outside these limits, the associated switch assembly may require service or replacement. Operation 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com 7 sales@calcert.com HARS-X and X2 4.2 Schematic Refer to Figure 4-1 for a schematic of the HARS decade unit. Figure 4-1. HARS Series Schematic Diagram 8 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com Maintenance sales@calcert.com HARS-X and X2 4.3 Replaceable Parts List Model Ref 1 2 3 4 Not Shown Not Shown Not Shown Not Shown Not Shown Not Shown Not Shown Not Shown Not Shown Not Shown Not Shown Not Shown Table 4.2: Replacement List IET Pt No BP-1000-RD BP-1000-BK BP-1000-GN HARS-X-4300-KNB HARS-X-3100 HARS-4100-X-.001 HARS-4100-X-0.01 HARS-4100-X-0.1 HARS-4100-X-1 HARS-4100-X-10 HARS-4100-X-100 HARS-4100-X-1k HARS-4100-X-10k HARS-4100-X-100k HARS-4100-X-1M HARS-4100-X-10M Description Binding Post, Red Binding Post, Black Binding Post, Green Knob Assembly Foot 1 m/step Decade Switch Assembly 10 m/step Decade Switch Assembly 100 m/step Decade Switch Assembly 1 /step Decade Switch Assembly 10 /step Decade Switch Assembly 100 /step Decade Switch Assembly 1 k/step Decade Switch Assembly 10 k/step Decade Switch Assembly 100 k/step Decade Switch Assembly 1 M/step Decade Switch Assembly 10 M/step Decade Switch Assembly * Use "X2" for higher power model, for example HARS-4100-X2-100 for 100 /step Decade X2 Switch Assembly 4 1 2 3 Figure 4-2. HARS Replaceable Parts Maintenance 1.888.610.7664 15 10 20 5 25 0 30 www.calcert.com 9 sales@calcert.com