Time Electronics 1041 Resistance Decade Box Instruction Manual

1041
Resistance Decade Box
User Manual
Version 1.2

Introduction

A low ohm resistance box designed for general laboratory work including platinum resistance thermometry. The 1041 is compact and durable, housed in a robust metal case with removable protective rubber cover. Excellent accuracy is achieved by using high stability metal film resistors.
The 5-digit thumbwheel switch makes selecting and reading the resistance setting easy.
The 1041 incorporates colour coded digits: ohms – white, milliohms – yellow.
Special attention has been given to maximize the reliability of operation. A special multiple gold contact switch arrangement ensures that a back-up contact is always available to take over should a failure occur.
For connections the unit features safety terminals that are compatible with 4 mm shrouded plugs, as well as standard plugs, bare wires, and spade terminals.
The 1041 comes fitted with an ergonomic rubber cover providing increased protection and durability. It has a textured grip for comfortable handling, and side openings to place labels. It is easy to remove if you prefer a stand- alone unit or to use the optional 9026 carry case.
Features

• 0.01 Ω to 1 kΩ
• High accuracy
• Clear visual indication
• High stability
• Low temperature coefficient
• Safety terminals
• Removable protective cover
• Suitable for industry or education

Specifications

Resistance range ……………… 0.01 Ω to 1 kΩ in 0.01 Ω steps

Decade (9 steps each)| 0.01 Ω| 0.1 Ω
± 5 %| 1 Ω| 10 Ω
± 0.5 %| 100 Ω
---|---|---|---|---|---
Accuracy| ± 10 %| ± 1 %| ± 0.1 %
Max current| 1.0 A| 1.0 A| 1.0 A| 0.3 A| 0.1 A
Max voltage| 90 mV| 900 mV| 9 V| 27 V| 90 V
Voltage DC per step| 10 mV| 100 mV| 1 V| 3 V| 10 V

NOTE: On all ranges 0.01 Ω up to 100 Ω, the maximum applied voltage is proportional to the set point, keeping the current at or below the maximum specified.

A third safety terminal is to enable the case to be earthed or connected to either output.
Dimensions|  W200 x H75 x D110 mm
(215 x 100 x 120 mm including supplied protective cover).
Weight| 0.6 kg (1.0 kg including protective cover)
Options| Calibration certificates, carry case.
Country of origin| United Kingdom.

Ordering Information

Operation

3.1 Safety Precautions
****Observe proper safety operational guidelines when working with high voltages.
To minimize shock hazard connect the case terminal to an electrical ground.
Always take precautions to avoid and prevent contact with live components.
Handle the unit with care and use as per the instructions in this manual.

3.2 Front Panel Controls and Connections

• Resistance Terminals: Resistance is connected via the safety terminal binding posts that are suitable for twisted stripped wire compression connection, spade terminals, or by 4 mm shrouded or normal plug insertion.
• Case Terminal: The case terminal is isolated from the two active resistance terminals. When connected to ground/earth, it may be used as a guard or shield connection, this can help to reduce unwanted electrical noise pickup, and help maintain the case at a safe voltage in certain modes of use.
• 5-way Digit Decade Bank: Used for selecting the required resistance by setting the thumbwheel digit switches to the value of the decade range. Each decade can be set from 0 to 9.

3.3 Operating Instructions
3.3.1 Connections

Connection to the decade box is via 4 mm safety terminal posts, using 4 mm shrouded or standard plugs. Alternatively, crocodile clips or stripped wire connections can be used.
Whatever method is used, the connection must be tight to the terminal posts to avoid introducing unwanted additional resistance.
The red and black active terminals connect to the resistance elements, and the green terminal is connected to the case for screening purposes.
**For certain applications, the user may want to connect the case terminal to either of the active terminals. This can be done, but the case would then be at the same potential as the active terminals. The user should be aware that this could be hazardous and safety precautions must be taken to prevent electric shock.
3.3.2 Setting Resistance**

Before use it is recommended that all the digit thumbwheels are rotated completely 2 times.
This will ensure the contacts are self-cleaned, maximizing their low contact resistance.
This is particularly beneficial if the decade box has not been used for a long time.
It is imperative that the switch setting should be unambiguous to avoid misreading the set value. To prevent misreading, the 1041 incorporates a colour coding system to divide the setting into 2 groups corresponding to ohms and milliohms.
To set resistance, use the thumbwheel digit switches to set the required values according to the decade ranges.
For example, to simulate 138.51 Ω equivalent to 100 °C Pt100 (ITS-90):

• Set the 100 Ω bank switch to 1.
• Set the 10 Ω bank switch to 3.
• Set the 1 Ω bank switch to 8.
• Set the 0.1 Ω bank switch to 5.
• Set the 0.01 Ω bank switch to 1.

For a quick reference to the setting values of the 1041, please see the Resistance Setting
Table on the following page.
Note: All resistance boxes have a residual resistance, meaning that when the dials are set to zero a small resistance remains. If you are making precision measurements or recalibrating the instrument, this residual value must be subtracted from all measurements.
Typical values of residual resistance are shown in the specifications.
For precise values relating to your specific unit, refer to calibration certificate (if ordered).
3.4 Resistance Setting Table
The below table shows the settings of each resistance decade using the dials.

| | | |
---|---|---|---|---
100Ω
Decade| 10Ω
Decade| 1Ω
Decade| 0.1Ω
0.2   Decade| 0.01Ω
Decade
Dial| Ω| Dial| Ω| Dial| Ω| Dial| Ω| Dial| Ω
0| 0 Ω| 0| 0Ω| 0| 0Ω| 0| 0Ω| 0| 0Ω
1| 100Ω| 1| 10Ω| 1| 1Ω| 1| 0.1Ω| 1| 0.01Ω
2| 200Ω| 2| 20Ω| 2| 2Ω| 2| 0.2Ω| 2| 0.02Ω
3| 300Ω| 3| 30Ω| 3| 3Ω| 3| 0.3Ω| 3| 0.03Ω
4| 400Ω| 4| 40Ω| 4| 4Ω| 4| 0.4Ω| 4| 0.04Ω
5| 500Ω| 5| 50Ω| 5| 5Ω| 5| 0.5Ω| 5| 0.05Ω
6| 600Ω| 6| 60Ω| 6| 6Ω| 6| 0.6Ω| 6| 0.06Ω
7| 700Ω| 7| 70Ω| 7| 7Ω| 7| 0.7Ω| 7| 0.07Ω
8| 800Ω| 8| 80Ω| 8| 8Ω| 8| 0.8Ω| 8| 0.08Ω
9| 900Ω| 9| 90Ω| 9| 9Ω| 9| 0.9Ω| 9| 0.09Ω

Applications

Pt100 Resistance Simulation
Accurate simulation of low ohm values, such as PRT, can be performed by using the 1041.
Resistance vs Temperature Relationship for Platinum Resistance Thermometer Detector Element (ITS-90)

Typical connections for 2,3 & 4 wire resistance
Thermometers

Using this technique, the current passed through to resistor can be limited to a known value, and lead resistance does not affect the accuracy of the readings.

Maintenance and Repair

Dismantling the Instrument
Remove the rubber protection cover then removal of four screws enables the metal case cover to be taken off which provides access to all parts of the instrument.
Repair
NOTE: No repair work should be undertaken by the customer while the instrument is under warranty as such work may render the warranty invalid.
Certain of the precision components used in this instrument are not readily available and make repairs by the customer difficult if these components are damaged.
Overload conditions can cause a unit failure
To avoid overload, power dissipation in the resistive elements must be kept below 1 W.
To achieve this the maximum current must not exceed that given in the RANGE table shown in specifications. Current will be proportional to the applied voltage. The maximum allowed working voltage that can be applied at the maximum setting for each range is also shown in the table.
If multiple banks are being used, the current must not exceed that of the lowest rated bank.
For example, if you set 107.79 Ω:

• The 100 Ω bank switch to 1.
• The 10 Ω bank switch to 0.
• The 1 Ω bank switch to 7.
• The 0.1 Ω bank switch to 7.
• The 0.01 Ω bank switch to 9.

In this setting the 100 Ω bank has the lowest current rating at 100 mA, therefore the current flowing through all the selected resistive elements in all the banks being used, must not exceed 100 mA.

Warranty and Servicing

Warranty
Time Electronics products carry a one-year manufacturer’s warranty as standard.
Time Electronics products are designed and manufactured to the highest standards and specifications to assure the quality and performance required by all sectors of industry.
Time Electronics products are fully guaranteed against faulty materials and workmanship. Should this product be found to be defective, please contact us using the below details. Inform us of the product type, serial number, and details of any fault and/or the service required. Please retain the supplier invoice as proof of purchase.
This warranty does not apply to defects resulting from action of the user such as misuse, operation outside of specification, improper maintenance or repair, or unauthorized
modification. Time Electronics’ total liability is limited to repair or replacement of the product. Note that if Time Electronics determine that the fault on a returned product has been caused by the user, we will contact the customer before proceeding with any repair.
Product Registration
You can register your product at: www.timeelectronics.com/contact/product- registration. Registering your product will enable us to maintain a record of purchase for your warranty. You can also use the web form to provide feedback about our products and services.
Calibration and Repair Services
Time Electronics offers repair and calibration services for all the products we make and sell.Routine maintenance by the manufacturer ensures optimal performance and condition of the product. Periodic traceable or accredited calibration is available.
Contacting Time Electronics
Online:
Please visit www.timeelectronics.com and select Technical Support from the Contact links. From this page you will be able to send information to the Time Electronics service team who will help and support you.
By phone: +44 (0) 1732 355993
By email:[email protected]
Returning Instruments 
Prior to returning your product please contact Time Electronics. We will issue a return merchandise authorization (RMA) number that is to accompany the goods returning.
Further instructions will also be issued prior to shipment. When returning instruments, please ensure that they have been adequately packed, preferably in the original packing supplied. Time Electronics Ltd will not accept responsibility for units returned damaged. Please ensure that all units have details of the service required and all relevant paperwork.
Send the instrument, shipping charges paid to:
Time Electronics Ltd
Unit 5, TON Business Park, 2-8 Morley Road,
Tonbridge, Kent, TN9 1RA.
United Kingdom.
Tel: +44(0)1732 355993
Fax: +44(0)1732 350198
Email: [email protected]
Web Site: www.timeelectronics.com
Disposal of your old equipment

1. When this crossed-out wheeled bin symbol is attached to a product it means the product is covered by the European Directive 2002/96/EC.
2. All electrical and electronic products should be disposed of separately from the municipal waste stream via designated collection facilities appointed by the government or the local authorities.
3. The correct disposal of your old appliance will help prevent potential negative consequences for the environment and human health.
4. For more detailed information about disposal of your old appliance, please contact your city office, waste disposal service or return to Time Electronics.

© 2022 Time Electronics Ltd.
All rights reserved.
Nothing from this manual may be multiplied, or made public in any form or manner, either electronically or hard copy, without prior written consent from Time Electronics Ltd. This also applies to any schematics, drawings and diagrams contained herein.
This manual provides operating and safety instructions for the Time Electronics product.
To ensure correct operation and safety, please follow the instructions in this manual.
Time Electronics reserves the right to change the contents, specifications and other information contained in this manual without notice.

Version 1.2
10-22
Time Electronics Ltd
Unit 5, TON Business Park, 2-8 Morley Road,
Tonbridge, Kent, TN9 1RA, United Kingdom.
T: +44 (0) 1732 355993 | F: +44 (0) 1732 350198
[email protected] | www.timeelectronics.com

Documents / Resources

| Time Electronics 1041 Resistance Decade Box [pdf] Instruction Manual
1041 Resistance Decade Box, 1041, Resistance Decade Box, Decade Box, Box
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References

• Time Electronics – Precision Test Instruments, Calibration Benches
• Product Registration Form | Time Electronics

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