Quick Installation Guide
The Rosemount HVD
Step 1: Installation
Step 2: Operating The HVD
Start
End
00825-0300-4840, Rev AA
November 2010
Rosemount HVD
Rosemount
Gauged Head Verification Device (HVD)
www.rosemount.com
Rosemount HVD
Emerson Process Management
Rosemount Division
8200 Market Boulevard
Chanhassen, MN USA 55317
T (U.S.) 1-800-999-9307
T (International) (952) 906-8888
F (952) 949-7001
www.rosemount.com
Emerson Process Management
Blegistrasse 23
P.O. Box 1046
CH 6341 Baar
Switzerland
T +41 (0) 41 768 6111
F +41 (0) 41 768 6300
Emerson Process Management
Asia Pacific Pte Limited
1 Pandan Crescent
Singapore 128461
T +65 6777 8211
F +65 6777 0947
Service Support Hotline: +65 677 0 8711
Enquiries@AP.EmersonProcess.com
Figure 1. Rosemount HVD
© 2010 Rosemount Inc. All rights reserved. All marks property of owner.
The Rosemount HVD
The HVD is a combined mounting bracket and
verification device (reference target) to check
and certify the Rosemount 3107 Ultrasonic
Level transmitter or 3108 Flow transmitter in an
open channel flow application.
• Valuable aid for instrument calibration,
commissioning and certification
• Easy reference check of calibrated flow
• Essential tool for setting the bottom
reference dimension of a tank
• Corrosion resistant stainless steel
construction
• Reinforced polypropylene target plate
Unreliable flow data can result in inefficient
plant operation and unnecessary investment in
plant upgrades. This is particularly true with
measuring industrial and municipal effluents,
and yet it is frequently given the least priority
and attention. Flow data obtained from a
dependable source enables plant to be
operated in an efficient manner. By optimizing
treatment processes, operators can ensure the
maximum treatment capacities are achieved,
before additional investment is made.
Open Channel Flow measurement systems
such as weirs and flumes, frequently use
non-contact ultrasonic level measuring
instruments to determine flow. The most
common cause of unreliable flow data is due to
inaccurate setting of the gauge zero and
measurement span of the ultrasonic device.
With the aid of the Head Verification Device
(HVD), regular flow system checks can be
carried out in a matter of minutes.
Quick Installation Guide
00825-0300-4840, Rev AA
November 2010
2
Quick Installation Guide
STEP 1: INSTALLATION
Figure 2. Typical Installation
00825-0300-4840, Rev AA
November 2010
Rosemount HVD
Installing The HVD
The HVD package includes a universal
mounting bracket designed to bolt directly to
standard Uni-Strut or similar mounting
system. The HVD should be assembled as
shown in the picture (Figure 2) and with
reference to the installation pictures on
page 5. It should be installed on a securely
mounted section of horizontal Uni-Strut or
suitable mounting system, such that the
retractable target can be lowered and rotated
under the ultrasonic sensor without
interference from the surrounding channel or
chamber. The HVD should be positioned
upstream of the flume or weir at a position as
recommended in the relevant ISO or BS
standard for the primary measuring device.
The target plate shaft is provided with a selection of holes to accept a dowel pin to enable
the optimum reference height to be set with relation to the invert level of the flume or vertex
of the weir. After final assembly and when the structure is fully tightened and aligned, the
exact HVD reference height should be determined using a suitable optical or laser level. The
target plate should be set to represent a level reading of 75% to 90% of the maximum span.
This enables the target to be lowered and rotated under the sensor and to simulate a flow
reading within the normal measurement span.
Calculating The Transmitter Mounting Height
To minimize the measurement uncertainty, it is recommended to mount the transmitter as
low as possible in the flume approach section or weir chamber. As a typical guide, the
optimum height or reference height (3107/3108 parameter P010) should be calculated as
follows:
P010 = Maximum Gauged Head + Transmitter Deadband + 2 in.
Where:
Transmitter Deadband = 12 in. for 3107 and 3108
For example, consider a rectangular weir application using a Rosemount 3108 transmitter
and Rosemount 3490 controller, where the maximum flow to be measured is 2000 gallons
per minute and the maximum gauged head is 14 in.
The transmitter reference height above the datum (P010) is calculated as follows:
NOTE:
Ensure the Transmitter Base Units are set to the required units (in., ft. or m)
H
= 14 in. and 3107/3108 Minimum Transmitter Deadband = 12 in.
max
Therefore, Transmitter Height (P010) = 14 in. + 12 in. + 2 in. = 28 in.
3
Quick Installation Guide
STEP 2: OPERATING THE HVD
Rosemount HVD
In the example above, the HVD should be mounted in the weir chamber so that transmitter
face is minimum of 28 in. above the datum level which, in this case, is the horizontal sill of
the weir. An allowable tolerance for this height is ±1 in. as this will be set precisely when the
transmitter is calibrated using the target plate on the HVD.
00825-0300-4840, Rev AA
November 2010
Setting The HVD Target Plate Reference Height
The HVD system comes fully assembled. If further adjustment is needed to achieve the
desired height of the transmitter, it may be necessary to adjust the relative position of the
transmitter mounting bracket on the main HVD assembly. This is achieved by removing the
two countersunk cap-head screws and locknuts, and re-positioning the bracket as required.
If the target plate height needs to be adjusted in the “READ” position, remove the locking pin
from the main 0.5 in. diameter stainless steel shaft and re-fit to achieve a reference height
as detailed in the example below.
Rectangular Weir - Q
= 14 in.
H
max
Sensor Height Above Datum = 28 in. (result from previous calculation)
Therefore, Target Height Above Zero Datum = 0.9 * H
Or = 0.75 * H
Operating the HVD
max
When the HVD has been finally adjusted to achieve a target height (as described above),
the transmitter readings can be verified after the exact reference height has been measured.
The most convenient way to measure the actual reference target height above the datum
level is to use an optical or laser level. This normally involves using a surveyors' staff (or
similar rigid pole or rule) and observing the relative heights of the target and datum by using
the optical level. To be more precise with the measurement, a suitable ruler can be
temporarily fixed to the staff to allow a more accurate reading. The actual height of the
reference target is taken as the difference between the target plate level and the datum
level.
When the exact reference target height is known, the target plate should be lowered down
and moved directly underneath the transmitter to simulate a level or flow reading. If the 3107
or 3108 is being used with a Rosemount 3490 controller, the display can be configured to
indicate the actual level being measured by the transmitter. This is normally the PVin value
which is the Primary Variable (level in inches) being sent to the 3490 controller. Alternatively,
this can be read from the “MONITOR” option on the 3490 main menu.
The target plate should be left under the transmitter for a minimum of three minutes to
provide a stable reading for the level. If the transmitter bottom reference or reference height
P010 has been set correctly, the transmitter should indicate a level reading corresponding to
the actual reference target height.
If the transmitter needs to be adjusted to achieve a correct reading, the transmitter’s bottom
reference parameter P010 can be adjusted in two ways. Either calculate the error in the
reading and correct for this by re-setting P010 by the required offset, or using the Set-up
menu on the 3490 controller to go to transmitter Set-up and select “Depth now”. When
prompted, enter the actual level and confirm “Depth now”. The 3490 will automatically
configure parameter P010 to the correct value to read the true target plate height.
= 2000 GPM
max
= 0.75 * 14 in. = 10.5 in. (Min.)
= 0.9 * 14 in. = 12.6 in. (Max.)
max
4
Quick Installation Guide
6.42
(163)
2.05
(52)
1.97
(50)
Fixing
Hole
Ø11
Locking PlateLocking Plate
Preferred Mounting
On UniStrut
(Customer Supplied)
RETRACTED
POSITION
9.61
(244)
Target Plate:
Shown In Locked Position.
Lower and Swing 90 Degrees
To Operating Position To
Verify Transmitter Reading
28.0
(711)
Note: Ensure Liquid Level
Is Below Target Plate When
Taking Measureme nts
1.97
(50)
Liquid Level
00825-0300-4840, Rev AA
November 2010
Rosemount HVD
Figure 3. Dimension Drawings
Note: Dimensions Are Shown In Inches (mm)
5
Rosemount HVD
OPERATING
POSITION
Locking Position ‘A’
5 Holes 25 Spacing
X
‘X’ Distance Should Be Set By Selecting The
Appropriate Pin Position ‘A’. The Target
Reference Is Typically Between 75% and 90%
Of The Maximum Span. This Distance Must
Be Greater Than The Transmitter Range
(Deadband), typically 11.8 in. (300 mm)
1.97
(50)
8.39
(213)
Note: Ensure Liquid Level
Is Below Target Plate When
Taking Measureme nts
Liquid Level
Quick Installation Guide
00825-0300-4840, Rev AA
November 2010
Note: Dimensions Are Shown In Inches (mm)
6
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