Guildline 7520 Guide

OPERATION AND INSTRUCTION MANUAL
FOR
MODEL 7520
PRECISION VOLTAGE DIVIDER
www.guildline.com
NOTICE
The contents and information contained in this manual are proprietary to Guildline
Instruments Limited. They are to be used only as a guide to the operation and
maintenance of the equipment with which this manual was issued, and may not be
duplicated or transmitted by any means, either in whole or in part, without the written
permission of Guildline Instruments Limited.
OM7520-B-00
27 September, 2019

WARRANTY AND SERVICE
CERTIFICATION: Guildline Instruments Limited certifies that this product was tested
and inspected and found to meet its published specifications when it was shipped from
the factory.
WARRANTY: This product is warranted against defects in materials and workmanship
for a period of two years from date of shipment. During the warranty period, Guildline
Instruments Limited will, at its option, either repair or replace products that prove to be
defective.
SERVICE: For warranty service or repair, this product must be returned to the factory.
The buyer shall prepay shipping charges to Guildline Instruments Limited and Guildline
Instruments Limited shall pay surface shipping to the buyer. Permission must be
obtained from the factory for warranty repair returns.
LIMITATIONS: The foregoing warranty shall not apply to defects resulting from
improper or inadequate maintenance by the buyer, or unauthorized modifications or
misuse.
Neither Guildline Instruments Limited nor any of its employees shall be liable for any
direct or indirect, special, incidental or consequential damages arising out of the use of
this product.
No other warranty is expressed or implied.
SAFETY PRECAUTIONS
This product has been designed and tested in accordance with IEC1010-1/EN61010-1
including amendment 1(1995) for insulation category II use. Use of this equipment in a
manner not specified could result in personal injury.
AC POWER SOURCE: This product is intended to operate from an ac power source
that will apply not more than 264 V ac between either of the supply conductors and
ground.
POWER CORD: Use only the power cord and connector appropriate for the voltage
and plug configuration in your country. The cord must contain a safety ground conductor
and be connected to a plug that has a connection to earth ground. Use only a power cord
that is in good condition.
SIGNAL INPUT POWER: Signals applied to the input or output terminals must be
limited to levels deemed safe by the IEC/EN specifications. When applied voltages are
above 30 volts, the current source must limit the current to not more than 2 milliamps.

OM7520-B-00
27 September, 2019
i
TABLE OF CONTENTS
1. INTRODUCTION.................................................................................................. 1-1
1.1. DESCRIPTION.....................................................................................................................................1-1
1.2. WARRANTY.........................................................................................................................................1-1
1.3. TO OBTAIN WARRANTY SERVICE...............................................................................................1-3
1.4. SPECIFICATIONS...............................................................................................................................1-4
2. INSTALLATION ................................................................................................... 2-1
2.1. INITIAL INSPECTION .......................................................................................................................2-1
2.2. POWER REQUIREMENTS................................................................................................................2-1
2.3. LOCATION ...........................................................................................................................................2-1
2.4. WARM-UP AND SELF ALIGNMENT ..............................................................................................2-2
3. MANUAL OPERATION........................................................................................ 3-1
3.1. FRONT PANEL ....................................................................................................................................3-1
3.2. REAR PANEL.......................................................................................................................................3-2
3.3. FRONT PANEL OPERATION ...........................................................................................................3-3
3.4. TOUCH SCREEN DISPLAY FUNCTIONS ......................................................................................3-4
3.4.1. Opening Banner/Main Display Screen ...............................................................................................3-4
3.4.2. Divider Menu Screen..........................................................................................................................3-5
3.4.3. Comparator Menu Screen...................................................................................................................3-7
3.4.4. Setup Menu Screen.............................................................................................................................3-8
3.4.4.1. Self-Alignment Screen..............................................................................................................3-9
3.4.4.2. Password Screen .....................................................................................................................3-12
3.4.4.3. Offset Adjustment Screen .......................................................................................................3-13
3.4.4.4. System Parameters Screen ......................................................................................................3-15
3.4.5. Status Screen.....................................................................................................................................3-17
3.4.6. Log Screen........................................................................................................................................3-17
3.5. CONNECTION AND VOLTAGE DIVIDER INSTRUCTIONS....................................................3-18
3.6. 1:1 RATIO DIVIDER .........................................................................................................................3-18
3.7. 10:1 RATIO DIVIDER .......................................................................................................................3-19
3.8. 100:1 RATIO DIVIDER .....................................................................................................................3-19

OM7520-B-00
27 September, 2019
ii
3.9. 1000:1 RATIO DIVIDER ...................................................................................................................3-19
3.10. CONNECTION AND VOLTAGE COMPARISON INSTRUCTIONS .........................................3-20
3.11. 0.01 VOLT, 1:1000 RATIO COMPARISON....................................................................................3-21
3.12. 0.1 VOLT, 1:100 RATIO COMPARISON........................................................................................3-21
3.13. 1 VOLT, 1:10 RATIO COMPARISON.............................................................................................3-21
3.14. 10 VOLT, 1:1 RATIO COMPARISON.............................................................................................3-22
3.15. 100 VOLT, 10:1 RATIO COMPARISON.........................................................................................3-22
3.16. 1000 VOLT, 100:1 RATIO COMPARISON.....................................................................................3-22
4. THEORY OF OPERATION................................................................................... 4-1
4.1. INTRODUCTION.................................................................................................................................4-1
4.2. LOW THERMAL DESIGN .................................................................................................................4-1
4.3. INTERNAL CIRCUITS .......................................................................................................................4-2
4.4. CIRCUIT PROTECTION....................................................................................................................4-2
4.5. COMPARISON MEASUREMENT CONFIGURATIONS...............................................................4-3
4.6. MEASUREMENT CONFIGURATION A: 0.01 VOLT COMPARISON ......................................4-4
4.7. MEASUREMENT CONFIGURATION B: 0.1 VOLT COMPARISON.........................................4-4
4.8. MEASUREMENT CONFIGURATION C: 1 VOLT COMPARISON ...........................................4-4
4.9. MEASUREMENT CONFIGURATION D: 10 VOLT COMPARISON .........................................4-4
4.10. MEASUREMENT CONFIGURATION E: 100 VOLT COMPARISON........................................4-5
4.11. MEASUREMENT CONFIGURATION F: 1000 VOLT COMPARISON......................................4-5
4.12. INTERNAL RATIO ALIGNMENT....................................................................................................4-5
5. MAINTENANCE AND TROUBLE SHOOTING.................................................... 5-1
5.1. PERIODIC MAINTENANCE .............................................................................................................5-1
5.2. UNSTABLE READINGS .....................................................................................................................5-1
5.3. ALIGNMENT........................................................................................................................................5-1
5.4. SERVICE...............................................................................................................................................5-1

OM7520-B-00
27 September, 2019
iii
6. REMOTE CONTROL............................................................................................ 6-1
6.1. REMOTE OPERATION......................................................................................................................6-1
6.2. REMOTE COMMANDS......................................................................................................................6-2

OM7520-B-00
27 September, 2019
iv
LIST OF FIGURES
FIGURE 1-1: GUILDLINE MODEL 7520 PRECISION VOLTAGE DIVIDER.............................................1-1
FIGURE 3-1: FRONT PANEL GUILDLINE MODEL 7520..............................................................................3-1
FIGURE 3-2: REAR PANEL GUILDLINE MODEL 7520.................................................................................3-2
FIGURE 3-3: GUILDLINE MODEL 7520 MENU/SCREEN HIERARCHY ...................................................3-3
FIGURE 3-4: MODEL 7520 CONNECTIONS FOR OPERATION AS A VOLTAGE DIVIDER...............3-18
FIGURE 3-5: MODEL 7520 CONNECTIONS FOR COMPARISONS UUT TO 10 VOLTS.......................3-20
FIGURE 4-1: 7520 COMPARISON MEASUREMENT CONFIGURATIONS................................................4-3

Section 1
OM7520-B-00
27 September, 2019
1-1
1. INTRODUCTION
1.1. DESCRIPTION
The Guildline Precision Voltage Divider, with extremely low thermal offsets and built-in
temperature controlled chamber, is ideal for voltage ratio measurements to sub-ppm
accuracy. Input voltages in the range of 10 mV to 1100 V can be divided by ratios of
1:1000, 1:100, 1:10, 1:1, 10:1, and 100:1 with accuracies of 0.5, 0.2, 0.1, 0.05, 0.1, and
0.2 µV/V respectively.
Special care has been taken to minimize thermal offsets and noise. The switches used are
high isolation, low thermal relays. The 7520 can be operated from the front panel touch
screen or by SCPI commands sent over the USB or IEEE Interfaces.
Figure 1-1: Guildline Model 7520 Precision Voltage Divider
The voltage divider is fully controlled by an internal micro-processor through a front
panel touch screen.
1.2. WARRANTY
Each Model 7520 Precision Voltage Divider provided includes a two (2) year warranty in
which Guildline Instruments warrants that the unit is free from defects in material,
workmanship, manufacturing, and design and will perform to or exceed specifications, if
operated properly, for the duration of the two (2) year warranty coverage. This warranty
only extends to the intended original purchaser.

Section 1
OM7520-B-00
27 September, 2019
1-2
Guildline will repair or replace any failed unit at no additional cost to the customer.
Guildline will be responsible for returning warranty standards to the owner and will bear
transportation costs from the repair center back to the user. It will be the customer’s
responsibility for transportation costs for equipment returned to Guildline for repair or
replacement. Warranty repairs will be provided in Canada.
Guildline does not provide warranty service or file claims due to shipping damage.
Customers are responsible for properly packaging instruments and insuring
instruments, to account for the possibility of shipping damage.
These warranties will not, in any way, be voided by any customer performed routine
maintenance accomplished in accordance with Guildline's service procedures (e.g.
replace fuses, adjust instrument in accordance with calibration instructions, lubrication,
cleaning, etc.).