Teledyne DAVC-4 User manual

Digital AVC
INSTRUCTION MANUAL
(DAVC-4, DAVC-5, DAVC-6)
www.teledyne-hi.com
ISO 9001
CERTIFIED

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Manual Print History
The print history shown below lists the printing dates of all revisions and addenda created for this
manual. The revision level letter increases alphabetically as the manual undergoes subsequent
updates. Each new revision includes a revised copy of this print history page.
Revision A (Document Number 174-062009) .......................................................................June 2009
Revision B (Document Number 174-072009) ........................................................................July 2009
Revision C (Document Number 174-072009)........................................................................July 2009
Revision D (Document Number 174-062010).......................................................................June 2010
Revision E (Document Number 174-082010) ...................................................................August 2010
Revision F (Document Number 174-112014) ............................................................. November 2014
Revision G (Document Number 174-072015)........................................................................July 2015
Revision H (Document Number 174-052016).......................................................................May 2016
Revision J (Document Number 174-012021) ................................................................... January 2021
Visit www.teledyne-hi.com for WEEE disposal guidance.
Hastings Instruments reserves the right to change or modify the design of its equipment
without any obligation to provide notification of change or intent to change.

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Table of Contents
1.0 GENERAL INFORMATION ........................................................................................................................................4
1.1 FEATURES ...............................................................................................................................................4
1.2 SAFETY ...................................................................................................................................................4
1.3 COMPLIANCE DATA ................................................................................................................................4
1.4 SPECIFICATIONS ......................................................................................................................................5
1.5 THERMAL COEFFICIENT..........................................................................................................................5
1.6 ACCESSORIES ..........................................................................................................................................6
2.0 INSTALLATION ............................................................................................................................................................9
2.1 POWER-I/O CABLE ..................................................................................................................................9
2.2 POWER REQUIREMENTS &PIN OUT.........................................................................................................9
2.3 SERIAL COMMUNICATIONS PIN OUT .......................................................................................................9
2.4 LINEAR OUTPUT PIN OUT.......................................................................................................................9
2.5 NON-LINEAR OUTPUT PIN OUT..............................................................................................................9
2.6 PRESSURE ALARMS PIN OUT .................................................................................................................10
3.0 VACUUM GAUGE OPERATION .............................................................................................................................11
3.1 QUICK START .......................................................................................................................................11
3.2 SETTING PRESSURE UNITS OF MEASURE ...............................................................................................11
3.3 NON-LINEAR ANALOG PRESSURE MEASUREMENT.................................................................................12
3.4 LINEAR ANALOG PRESSURE MEASUREMENT .........................................................................................14
3.5 ALARM SET POINT.................................................................................................................................17
3.6 DIGITAL COMMUNICATIONS.................................................................................................................18
3.7 OPERATION AND PERFORMANCE ...........................................................................................................20
3.8 GAUGE TUBE OPERATING PRINCIPLE....................................................................................................20
3.9 CALIBRATION PROCEDURE....................................................................................................................21
4.0 WARRANTY ................................................................................................................................................................23
4.1 WARRANTY REPAIR POLICY ..................................................................................................................23
4.2 NON-WARRANTY REPAIR POLICY .........................................................................................................23

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This manual contains technical and general information relating to the installation, operation, and
calibration of vacuum gauges and gauge tubes manufactured by Teledyne Hastings Instruments (THI).
For best performance, THI vacuum gauges should be operated with the appropriate THI gauge tube.
Attempting to use a THI vacuum gauge with another manufacturer’s tubes may result in damage to both
the gauge and tube.
1.1 Features
The THI Digital AVC (DAVC) is a digital readout version of THI’s AVC vacuum gauge. The heated gauge
tube supplies an analog, non-linear signal that is amplified for a zero to one-volt signal output. A precision
A/D converter, in conjunction with a microprocessor, measures the gauge tube’s signal output, converts
the measurement to a pressure reading using the gauge tube’s well defined output/pressure function, and
then provides the result to the end user through a serial communications port. In addition, the same
signal is converted to a linear analog output that is range selectable by the user.
The DAVC is available for use with three of THI’s most popular gauge tube families: The DV-6, DV-5, and
DV-4. The DV-6 range is 1.0 - 1000 mTorr. The DV-5 range is 0.1 – 100 mTorr. The DV-4 range is 0.2 –
20 Torr. All gauge-tubes used with the Digital AVC feature long life and minimal maintenance due to the
use of rugged, noble-metal, thermocouple (TC) gauge tubes that are designed specifically for each range.
1.2 Safety
The following symbols and terms may be found on THI products and/or in THI manuals and indicate
important information.
When found on the device, this symbol indicates that the operator should refer to the manual
for important instructions on the proper use of this device. When found in a manual, this symbol
indicates that the reader should understand the implications contained in the text before
operating the device.
The WARNING label indicates important information that should be heeded for safe and proper
performance of the device.
The label, CAUTION, is used to indicate that damage to the power supply or equipment connected to it,
could occur if directions are not followed. Warranty could be invalidated if the instructions in this manual
are not followed.
1.3 Compliance Data
1.0 General Information
CE Standard Compliance
Test Standard
SAFETY EN61010
EMC/EMI Family EN61326
CONDUCTED/RADIATED EN55011
ESD EN61000-4-2
RF EN61000-4-3
CONDUCTED IMMUNITY EN61000-4-6

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1.4 Specifications
Input Power ...............................................................................................................................11 – 32 VDC
.......................................................................................................................................................0.7 Watts
Cable .................................................................Combination power and RS232 cable, 1.5 meters, included
..........................................................................For CE Compliance, cable should never exceed 3.0 meters
Weight (Approx.) ........................................................................... 0.27 lbs (123 Grams) W/O Tube & Cable
Height (Length)........................................................................................................ 2.6”, W/O Tube & Cable
Width / Depth ........................................................................................................................................1.75”
Operating temperature Range ................................................................................................-20°C to 70°C
Standard Metal Gauge Tube...................................................................................(DV-6R, DV-5M, DV-4R):
Overpressure (Gauge tubes) .....................................................................................................50 psig max.
Material of Construction........................................................................................DAVC Housing: Aluminum
................................................................................................................Thermocouple: Glass, Noble Metal
Connections............................................................................................. High Density, 15-Pin, D Connector
............................................................................................................ Octal Tube Socket for Thermocouple
Alarms ................................................................................................................................. 0.50 Amps max.
Tube Leak Test...........................................................................................................<1x10-8 atm cc/sec He
Accuracy..................................................................... DV4, 0.02 – 20 Torr, ± (20% of Reading + 0.01 Torr)
Accuracy................................................................... DV5, 0.1 – 100 mTorr, ± (20% of reading + 0.2 mTorr)
Accuracy...............................................................DV6, 0.001 – 1.0 Torr, ± (15% of Reading + 0.001 mTorr)
Non-Linear Analog Output ............................................................................................................... 0-1 VDC
Linear Analog Output ...................................................................0-1, 0-5, 0-10, VDC and 0-20mA, 4-20mA
Digital Output............................................................ RS232 (9600 / 19.2k baud) (6-pin modular connector)
AC Tube Drive ....................................................................... 0.3 – 0.4 VAC, true RMS, 1 kHz square wave
AC Tube Drive ..................................................................... (Compatible with DV-4, DV-5, and DV-6 tubes)
Tube Input .................................................... 0 – 10 mVDC, (compatible with DV-4, DV-5, and DV-6 tubes)
Single Set Point Output............................................................... Open-collector transistor for over set point
Single Set Point
See tube Product Bulletin for available tube connection configurations.
1.5 Thermal Coefficient
The DAVC generates an AC voltage using an internal transformer. This heating voltage is supplied to
the vacuum tube to warm up the thermocouples in order to measure the pressure. As the ambient
temperature increases or decreases, the internal resistance of the copper winding in the transformer
also changes. This resistance change will change the AC heating voltage that the vacuum tube
receives. It will also change the pressure reading slightly. The typical rate of change for a given tube
type is given below:
DV6 0.2 mTorr/°C + 0.25% of reading/°C
DV5 0.08 mTorr/°C + 0.16% of reading/°C
DV4 2.6 mTorr/°C + 0.1% of reading/°C

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Increasing the temperature will cause the pressure readings to increase, while decreasing temperature
will cause the pressure readings to decrease. The instruments are initially adjusted at an ambient
temperature of approximately 22°C. This effect can be corrected by adjusting the low pressure reading at
the operating ambient temperature. The specified rate of change does not include any changes due to
thermal effects on the vacuum tube or actual changes in pressure that occur in a vacuum system during
temperature excursions.
1.6 Accessories
1.6.1 Installation Accessories
THI offers a complete line of system attachments that permit easy maintenance for contaminated
operations. Gauge tubes are offered with various system fittings to match almost any system
requirement. Additionally, THI’s complete line of quick disconnect attachments allows customers to install
these special fittings and easily replace sensors without vacuum sealant or Teflon® tape. For particularly
dirty systems, Hastings offers a particle dropout trap containing a series of nine separate baffles which
prevent solid contaminants from having a direct path to the sensor’s thermopile.
1.6.2 DV-6S: New DV-6 tube For Severe Environments
Hastings Instruments has developed a new gauge tube, the DV-6S, which is specifically designed for
outdoor use on cryogenic tanks including railcar and tanker truck applications. In addition to the DAVC,
the gauge tube is compatible with the hand-held HPM-4/6 and the analog VT-6.
The DV-6S is supplied with a protective cap. The O-ring-sealed cap protects the gauge tube pins from
moisture thus significantly reducing corrosion. A metal lanyard prevents cap loss. The tube is provided
with a standard 1/8” NPT fitting; however special fitting requests can often be met.
1.6.3 Calibration Reference Tubes
THI Reference Tubes employ the same metal thermopiles used in all THI Vacuum Gauge Tubes. The
thermopile is sealed in a glass capsule that has been evacuated, baked, outgassed, and then aged to
ensure long-term stability. The sealed capsule is then housed in a protective metal shell to provide a
rugged, trouble-free assembly.
Once assembled, the reference gauge tube is accurately calibrated to precisely simulate a gauge tube at
a given operating pressure. It provides quick and easy instrument re-calibration by merely plugging the
instrument and, in the case of the DAVC, adjusting the HTR potentiometer until the display reads the
exact pressure noted on the reference tube.
Reference Tubes for use with DAVC
55-104
DB-20
Ref Tube (DV-6) for DAVC-6 Calibration
55-101
DB-16D
Ref Tube (DV-4D) for DAVC-4 Calibration
55-103
DB-18
Ref Tube (DV-5) for DAVC-5 Calibration

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1.6.4 Tube Types and Cables
Extension Cables for VT Series (DAVC)
55-3 OM-8-OFV 8 Ft Extension Cable
55-22
OM-12-OFV
12 Ft Extension Cable
65-53 OM-25-OFV 25 Ft Extension Cable
65-102 OM-50-OFV 50 Ft Extension Cable
55-142 OM-100-OFV 100 Ft Extension Cable
Vacuum Gauge Tubes 1000 mTorr Range
Stock #
Model #
Description
55-38 DV-6M
1/8” NPT Standard (Yellow base)
55-38R DV-6R
1/8” Ruggedized
55-38RS DV-6
1/8” NPT Rohs
Rugged
55-38S
DV-6S
1/8” NPT Rugged/Vibration
55-251 DV-6-KF-16
KF
-16TM
55-267 DV-6-KF-25
KF
-25TM
55-283
DV-6-VCR
VCRTM
55-38R-CF DV-6R-CF
Mini Conflat
TM
Vacuum Gauge Tubes 100 mTorr Range
55-19
DV-5M
1/8” NPT (Red Base)
55-230
DV-5M -VCR
VCRTM
Vacuum Gauge Tubes 20Torr Range
55-19
DV-4D
1/8” NPT (Purple Base)
55-19R
DV-4R
1/8” NPT Ruggedized
55-258
DV-4D-KF-16
KF-16TM
55-266
DV-4D-KF-25
KF-25TM
55-227
DV-4D-VCR
VCR
TM

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1.6.5 Outline Drawing

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2.1 Power-I/O Cable
The Power-I/O Cable is assembled at the factory as shown in Fig. 1. Its terminal end is finished with
stripped wire ends each tinned with lead free solder. This configuration is consistent with the previous,
analog version of the AVC and its color-coded wire assignment remains the same, as much as possible,
considering the additional features of the Digital version.
2.2 Power Requirements & Pin Out
Supply the DAVC with a well regulated, 11 to 32 VDC power source capable of providing at least 0.7.
Watts between Power Common pin 4 (blue/-) and Power pin 3 (green/+). See Fig. 1.
2.3 Serial Communications Pin Out
The transmit line of the DAVC, RS232 TX pin 15 (pink), must be connected to the receive pin of the serial
connector on the computer and the receive line, RS232 RX pin 14 (tan) must be connected to the
transmit pin of the serial connector on the computer. A third line, Digital Common, pin 8 (black), should
join the common pins on both the computer and the DAVC.
RS-232 communication may be established with baud rates of 9600 or 19200 only. The communication
conditions of the DAVC are fixed at 8 data bits, 1 stop bit, no parity and no handshaking. See the
SERIAL COMMUNICATIONS subsection under OPERATION for the command set.
2.4 Linear Output Pin Out
A linear analog signal output line, pin 11 (red), can be configured to supply the following ranges:
0-20 mA, 4-20 mA, 0-1 VDC, 0-5 VDC and 0-10 VDC. The range is selected by sending an RS 232
Output Select command found in section 3.4.3 and then following the DAC Calibration instructions in
section 3.7.
2.5 Non-Linear Output Pin Out
A non-linear analog signal output line, pin 7 (yellow) supplies only a 0 to 1 VDC signal corresponding to
the output range of the selected tube. This signal should be measured with respect to the Analog Signal
Common at pin 6 (violet). See the Pressure vs. Analog Output Curve that follows in Section 3.3.
2.0 Installation

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2.6 Pressure Alarms Pin Out
A single pressure set point controls two open collector circuits. Alarm 1, the over-pressure condition is
available through pin 1 (gray) and Alarm 2, the under-pressure condition available through pin 2 (brown).
The open-collector circuits will need to be supplied with power and current limiting resistance by the end
user.
The circuit example illustrated in Figure 2 is limited to the voltage limitations of the DAVC. The maximum
continuous current should be limited to no more than 0.5 amps to avoid damage to the DAVC. The end
user must consider the 0.7-watt requirement of the DAVC as well as the additional power requirements of
their added load(s).
The alarm transistors consist of two BCW66HTA’s. Should the end user elect to use separate power
sources for the DAVC and the relay circuit, they should consider that the maximum collector-emitter
voltage is 45VDC and the maximum continuous current should be limited to no more than 0.5 amps to
avoid damage to the DAVC.