Agilent Technologies E5080 Series User manual

Agilent Technologies
Agilent 
E5080 Series Cryogen
Monitor with Pressure
Control
User Guide

Notices
© Agilent Technologies, Inc. 2012
No part of this manual may be reproduced
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tion into a foreign language) without prior
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Manual Part Number
9100382900
Edition
Revision A, April 2012
Printed in USA
Agilent Technologies, Inc.
5301 Stevens Creek Boulevard 
Santa Clara, CA 95051 USA
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Safety Notices
CAUTION
A CAUTION notice denotes a haz-
ard. It calls attention to an operat-
ing procedure, practice, or the like
that, if not correctly performed or
adhered to, could result in damage
to the product or loss of important
data. Do not proceed beyond a
CAUTION notice until the indicated
conditions are fully understood and
met.
WARNING
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly per-
formed or adhered to, could result
in personal injury or death. Do not
proceed beyond a WARNING
notice until the indicated condi-
tions are fully understood and met.

E5080 Series Cryogen Monitor User Guide 1
Contents
1 Introduction
Safety 4
Compliance Notice 5
Important Notice 6
Disclaimer 6
Contact Information 7
Europe 7
USA 7
Agilent website (all countries) 7
2 Operation
Description and Specifications 10
E5084 - pressure regulation for twin cryogen magnets 10
E5083 - pressure regulation for refrigerated magnets 11
Technical specification 13
Operation 14
Overview 14
Connecting the E5080 to a magnet system 15
Using the Menu System 16
Troubleshooting 18
Problems that occur on E5084 and E5083 units 18
Problems that occur on E5084 unit only 19
Problems that occur on E5083 unit only 20
Helium probe hardware errors 22
Thermal sensor hardware errors 22
Gas Heater hardware error 22
Settings for Hyperterminal 23
To make advanced settings 24
To make serial cable pin connections 25
Using Hyperterminal to upload logged data 26
Command Instruction Set 27
General commands 27
Helium commands 28
Thermal channel commands 29
Pressure commands 30
Gas flow (E5084 only) 30
Gas heater (E5083 only) 30

2 E5080 Series Cryogen Monitor User Guide
Request command 31
Connector Pin Assignments 32

3
Agilent E5080 Series Cryogen Monitor with Pressure Control
User Guide
Agilent Technologies
1
Introduction
Safety 4
Compliance Notice 5
Important Notice 6
Contact Information 7

4 E5080 Series Cryogen Monitor User Guide
1Introduction
Safety
Clean the equipment case and front panel with a
non- abrasive non- water based cleaner.
Store or install the equipment within the following
environmental conditions:
The unit contains an internal lithium battery that should not
be removed or changed other than by Agilent personnel.
There are no consumable parts associated with the
instrument nor is there any preventative inspection or
maintenance associated with the operation of the
instrument.
There are no user maintainable parts within the instrument.
Should the unit require repair, return it to Agilent
Technolgies; see “Contact Information” on page 7.
Do not move the equipment after installation and connection
to a magnet.
WARNING
Isolate or disconnect from mains supply before opening this unit for any
reason. LIVE PARTS INSIDE.
WARNING
This equipment must be connected to an earthed mains supply. For
continued protection against risk of fire or electric shock, replace
fuses with the same type, rating and UL listing.
CAUTION
This equipment is not suitable for, and must not be used in areas
with flammable mixtures.
Ambient temperature range 5oC to 40oC
Relative humidity range 30% to 95% non- condensing
Atmospheric pressure :700 hPA to 1060 hPA

Introduction 1
E5080 Series Cryogen Monitor User Guide 5
Compliance Notice
Marking by the symbol indicates compliance of this
device to the EMC (electromagnetic compatibility) and LV
(low voltage) directives of the European Community. This
unit is to be installed and operated as detailed. Any
modification or maintenance procedure undertaken which is
not approved by Agilent Technologies UK Ltd could nullify
the marking of this product and lead to prosecution. A
'Declaration Of Conformity' in accordance with the above
directive has been made and is located at Agilent
Technologies, Yarnton, Oxfordshire, UK.

6 E5080 Series Cryogen Monitor User Guide
1Introduction
Important Notice
Inspect goods immediately on arrival for possible transit
damage, and notify Agilent Technologies within three days of
receipt of goods. Failure to do this invalidates any possible
claim.
Disclaimer
Every precaution has been taken in the preparation of this
publication. Agilent Technologies assumes no responsibility
for errors or omissions. Neither is any liability assumed for
damages resulting from the use of the information contained
herein.

Introduction 1
E5080 Series Cryogen Monitor User Guide 7
Contact Information
Europe
Address:
Agilent Technologies UK Ltd.
6 Mead Road
Oxford Industrial Estate
Yarnton, Oxfordshire OX5 1QU
Telephone Numbers:
To find contact information for your country, click the
following link, select your country, and then click Go.
http://www.chem.agilent.com/en- us/ContactUS/Pages/Contact
Us.aspx
USA
Address:
Agilent Technologies, Inc.
5301 Stevens Creek Blvd.
Santa Clara, CA 95051
Telephone Numbers:
Toll Free: [phone]
Agilent website (all countries)
To find contact information for your country, click the
following link, select your country, and then click Go.
http://www.chem.agilent.com/en- us/ContactUS/Pages/Contact
Us.aspx

8 E5080 Series Cryogen Monitor User Guide
1Introduction

9
Agilent E5080 Series Cryogen Monitor with Pressure Control
User Guide
Agilent Technologies
2
Operation
Description and Specifications 10
Operation 14
Troubleshooting 18
Settings for Hyperterminal 23
Command Instruction Set 27
Connector Pin Assignments 32

10 E5080 Series Cryogen Monitor User Guide
2Operation
Description and Specifications
The E5080 unit is available in two configurations. These
units are used to regulate the helium pressure within the
cryostats of conventional twin cryogen cryostats (E5084) and
refrigerated zero boil- off cryostats (E5083).
E5084 - pressure regulation for twin cryogen magnets
The twin cryogen cooled magnets are housed inside a helium
reservoir, which is supported from the neck turrets on the
top of the cryostat. These necks are in good thermal contact
with the cold gas which boils off from the helium reservoir.
Since the rate of cryogen boiloff inside a magnet cryostat is
influenced by the local atmospheric pressure, the necks
expand or contract a small amount when the pressure
changes and the flow of helium gas through the necks
changes. Since the magnet is hanging from these necks, it
moves up and down a small amount relative to the bore of
the cryostat.
For sites which experience large variations in atmospheric
pressure, the small movement of the homogeneous volume
with respect to the NMR sample volume can become
apparent. You can overcome this effect by isolating the
helium vessel from changes in atmospheric pressure, by
piping exhaust helium gas through the E5084 unit. The
E5084 actively regulates the flow of escaping helium gas so
that the pressure is kept at a constant set level, typically a
little higher than the maximum local pressure which will
generally be experienced.

Operation 2
E5080 Series Cryogen Monitor User Guide 11
Figure 1 Schematic of E5084 system operation
E5083 - pressure regulation for refrigerated magnets
Refrigerated magnets are cooled electrically by a coldhead
and compressor system. For zero boil- off magnets, the
coldhead used will have sufficient cooling capacity to
recondense helium gas as it boils off, plus additional
capacity designed in for contingency.
The additional cooling capacity of the coldhead causes the
He gas pressure within the helium can to be reduced below
the ambient atmospheric pressure outside. Unless the system
is manufactured completely vacuum tight this presents a risk
of air being drawn into the helium can from outside.
The E5083 pressure regulator maintains a constant positive
pressure in the helium can by controlling the current sent to
a resistive element inside the cryostat. Heat generated by the
resistor is actively regulated so that it balances the excess
cooling power of the refrigerator.

12 E5080 Series Cryogen Monitor User Guide
2Operation
Figure 2 Schematic of E5083 system operation

Operation 2
E5080 Series Cryogen Monitor User Guide 13
Technical specification
Environmental conditions
The equipment is designed to be safe within the following
environmental conditions:
Mains input voltage 100 - 230V ~
Mains input power (max) 75 VA
Mains input frequency 50-60 Hz
Fuse Rating T2AH 250V absolute max
Gas port pressure 1150hPA absolute max
Gas Heater output voltage
Gas Heater output current
Gas Heater output power
24V max
:800mA max
12W max
Isolated RS232 connection 
(9D socket)
9600 baud, 8 bits, 1 stop, and no parity.
Helium Probe Input Connector :9 way 'D' socket
Helium Probe resistance 0.2-0.05 /mm
The probe wire resistance varies from batch to batch. If the exact probe resistance
is required, contact Agilent with the probe serial number.
Excitation current 80-245mA dependent upon probe wire resistance
Probe length 100mm to 2000mm
Thermal sensor input
connections
9 way 'D' socket
Equipment classification Class 1
Ambient temperature range 10oC to 40oC
Relative humidity range 30% to 95% noncondensing
Atmospheric pressure 700 hPA to 1060 hPA

14 E5080 Series Cryogen Monitor User Guide
2Operation
Operation
Overview
Information is shown to the user on a two line LCD display
on the front of the unit. A 5- button keypad allows settings
to be changed.
The three operations accessible via the front panel are:
•Adjustment of the helium gas working pressure
•Switch to a rapid sampling mode for use when liquid
helium refill is taking place
•Mute the audio alarm signal
In normal operational, the display of data is static. In the
event of an alarm or error condition, the display alternates
between the normal display with the errors or alarms.
If for any reason the parameter displayed in the current part
of the display cycle is out of tolerance or in error, the lower
right hand part of the display shows the word "Error" and
the red front panel LED is illuminated.
When the display is showing an error condition, an internal
acoustic sounder sounds.
For more information relating to how the unit responds to
errors, see “Troubleshooting” on page 18.

Operation 2
E5080 Series Cryogen Monitor User Guide 15
Connecting the E5080 to a magnet system
Connections are made via the magnet cables / gas pipe as
required for the specific installation:
Do not connect any cables to "PRESSURE", "AUX INPUT",
"RELAY OUT", or "LN2".
In E5084 mode, exhaust helium gas leaves the unit from gas
port B and can optionally be routed through a floating ball
flow gauge to give a visual indication of gas flow. You can
also use this port to route gas into a helium recovery
system.
Gas port C is used to measure the ambient atmospheric
pressure. On earlier units, atmospheric pressure is measured
directly within the enclosure of the unit.
Figure 3 E5080 rear panel
The E5080 can measure the following items:
•Cryostat pressure
•Atmospheric pressure
•Helium level for two independent probes
•Thermal sensor reading for two independent sensors
•Gas flow rate (E5084 only)
Magnet E5084 E5083
Helium level cable Helium
(Not required if magnet
already has level
monitoring fitted)
Helium
Helium gas pressure
pipe
Gas port A Gas port A
Gas heater Not required Gas heater
Thermal sensor cable Not required Thermal

16 E5080 Series Cryogen Monitor User Guide
2Operation
The Helium level probes, thermal sensors may be enabled or
disabled as required by the magnet system.
The parameter display screen shows the helium level (if level
monitoring configured) and pressure of the helium vessel.
The E5083 model also displays the thermal sensor
temperature, the gas heater on time and an asterisk (*) if
the gas heater is ON.
If you press the 'Right' key, the display shows the helium
level for the secondary probe (if level monitoring is
configured) and the current atmospheric pressure. The
E5083 model also displays the secondary thermal sensor
temperature.
Using the Menu System
Figure 4 E5080 front panel
When in the menu system, Up and Down buttons move
between menu items.
Left and Right buttons adjust the value.
Center/Enter applies the value.
If an entry is left incomplete or the menu system is not
exited, a time- out of approximately one minute occurs.
CAUTION
Other than to set the unit into Helium Fill Mode, do not change any
parameters of the E5080 unit without first contacting Agilent. 

At the time of installation of the magnet, all parameters are correctly
set by Agilent field representatives. Communicate any error
condition indicated by the instrument to Agilent, who can advise you
on the correct remedial action.

Operation 2
E5080 Series Cryogen Monitor User Guide 17
To adjust the pressure
•Press Center/Enter then Down. Press Left/Right to alter
the value.
•Unit is mB and the step size is 1mB.
•When the operating pressure is adjusted via the front
panel, an automatic adjustment is also made to the upper
and lower pressure alarm settings. These are set 5 mB
above and below the operating pressure.
To change the Helium Fill mode
•Press Center/Enter then Down, Down, Center/Enter. 
Press Left/Right to alter the state.
•This procedure turns On or Off the fast sample action
which occurs about every 40 seconds as required when
helium filling.
•This has a 90- minute time out period after which normal
samples on an eight hour basis occur.
To mute an audible alarm condition
•To silence the audible alarm while it is active, press the
front panel down arrow key pad.
•Hold the key pressed for approximately five seconds and
release it.
•The sounder is then silenced.
•A message is automatically added to the Error Message
stream as displayed on the LCD screen, to the effect that
the audible alarm is muted.
•When the alarm situation is corrected, the mute is
automatically reset to Off, thus enabling any subsequent
audible alarm.

18 E5080 Series Cryogen Monitor User Guide
2Operation
Troubleshooting
This section contains descriptions of some common problems
to help the Installation Engineer to find the source of the
problem and ensure the proper operation of the unit.
Problems that occur on E5084 and E5083 units
Problem As detected by E5084/3 Alarm result Comments
Disconnected helium
cable
Helium hardware error Helium hardware
failure is detected
Detected one second after a
helium read is attempted
Open or disconnected
gas pipe
Pressure same or close
to atmospheric
Falling helium level
Low pressure alarm
very likely
Helium low alarm,
later
Within three seconds
Blocked gas pipe Pressure may be affected
Measured helium
pressure does not rise
Likely that a
pressure error is
triggered