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Representative image displayed of VFB-91D-SSV|Actual product may vary

VFB-91D-SSV

Series VF Visi-Float® Acrylic Flowmeter

Series VF Visi-Float® Acrylic Flowmeter

Series RM Rate-Master® Polycarbonate Flowmeter

2", 5" or 10" Scale, Interchangeable Bodies*
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The Series RM Rate-Master® Flowmeters are a line of general use, direct reading precision flowmeters suitable for both gas and liquid applications. This Series consists of 2" (51 mm), 5" (127 mm) and 10" (254 mm) scales that can be panel or surface mounted with optional precision metering valves. Within a given Series, the Rate-Master® flowmeter bodies can be instantly interchanged, allowing the piping to remain undisturbed, interchangeability of the ranges, and easy cleaning. *The Rate-Master® flowmeter bodies can be instantly interchanged within the same series scale size, allowing the piping to remain undisturbed, interchangeability of the ranges, and easy cleaning.

NOTE: Effective immediately, the brass valve (-BV) option has been discontinued and the stainless steel valve (-SSV) is the suggested replacement.

NIST CALIBRATION available in Product Configurator.

California Residents: Click Here for Proposition 65 WARNING.

Product Applications

  • Medical equipment
  • Air samplers
  • Gas analyzers
  • Pollution monitors
  • Chemical injectors
  • Cabinet purging
Starting at $47.05
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Grouped product items
Model Description Availability* Qty Price
RMA-1 Flowmeter, range .05-.4 SCFH air, no valve. 1-3 days*
$47.05
RMA-10 Flowmeter, range 20-200 SCFH air, no valve. 1-2 Weeks*
$47.05
RMA-11 Flowmeter, range 30-200 cc/min air, no valve. 1-3 days*
$47.05
RMA-12 Flowmeter, range 50-500 cc/min air, no valve. 1-3 days*
$47.05
RMA-13 Flowmeter, range 100-1000 cc/min air, no valve. 1-3 days*
$47.05
RMA-14 Flowmeter, range 200-2500 cc/min air, no valve. 1-3 days*
$47.05
RMA-150 Flowmeter, range 10-100 cc/min air, no valve. ±8% accuracy. 1-3 days*
$70.70
RMA-151 Flowmeter, range 5-50 cc/min air, no valve. ±8% accuracy. 1-3 days*
$70.70
RMA-2 Flowmeter, range .1-1 SCFH air, no valve. 1-3 days*
$47.05
RMA-21 Flowmeter, range 1-10 LPM air, no valve. 1-3 days*
$47.05
RMA-25 Flowmeter, range 10-100 LPM air, no valve. 1-2 Weeks*
$47.05
RMA-26 Flowmeter, range .5-5 LPM air, no valve. 1-3 days*
$47.05
RMA-10-SSV Flowmeter, range 20-200 SCFH air. 1-3 days*
$62.40
RMA-10-TMV Flowmeter, range 20-200 SCFH air. 1-2 Weeks*
$88.40
RMA-11-SSV Flowmeter, range 30-200 cc/min air. 1-3 days*
$62.40
RMA-6-SSV Flowmeter, range 2-20 SCFH air. 1-3 days*
$62.40
RMA-11-TMV Flowmeter, range 30-200 cc/min air. 1-2 Weeks*
$88.40
RMA-12-SSV Flowmeter, range 50-500 cc/min air. 1-3 days*
$62.40
RMA-7-SSV Flowmeter, range 5-50 SCFH air. 1-3 days*
$62.40
RMA-13-SSV Flowmeter, range 100-1000 cc/min air. 1-3 days*
$62.40
RMA-8 Flowmeter, range 10-100 SCFH air, no valve. 1-2 Weeks*
$47.05
RMA-14-SSV Flowmeter, range 200-2500 cc/min air. 1-3 days*
$62.40
RMA-8-SSV Flowmeter, range 10-100 SCFH air. 1-3 days*
$62.40
RMA-8-TMV Flowmeter, range 10-100 SCFH air. 1-3 days*
$88.40
RMA-9 Flowmeter, range 15-150 SCFH air, no valve. 1-3 days*
$47.05
RMA-150-SSV Flowmeter, range 10-100 cc/min air. ±8% accuracy. 1-3 days*
$86.05
RMA-9-SSV Flowmeter, range 15-150 SCFH air. 1-2 Weeks*
$62.40
RMA-151-SSV Flowmeter, range 5-50 cc/min air. ±8% accuracy. 1-3 days*
$86.05
RMA-9-TMV Flowmeter, range 15-150 SCFH air. 1-2 Weeks*
$88.40
RMB-49 Flowmeter, range .5-5 SCFH air. ±5% accuracy. 1-2 Weeks*
$61.35
RMA-1-SSV Flowmeter, range .05-.4 SCFH air. 1-3 days*
$62.40
RMB-49-SSV Flowmeter, range .5-5 SCFH air. ±5% accuracy. 1-3 days*
$79.05
RMB-50 Flowmeter, range 1-10 SCFH air. 1-2 Weeks*
$61.35
RMA-21-SSV Flowmeter, range 1-10 LPM air. 1-3 days*
$62.40
RMB-50D Flowmeter, range 1.2-10 SCFH/0.6-5 LPM air. 1-2 Weeks*
$61.35
RMB-50D-SSV Flowmeter, range 1.2-10 SCFH/0.6-5 LPM air. 1-3 days*
$79.05
RMA-22-SSV Flowmeter, range 2-25 LPM air. 1-3 days*
$62.40
RMB-50-SSV Flowmeter, range 1-10 SCFH air. 1-3 days*
$79.05
RMB-51 Flowmeter, range 2-20 SCFH air. 1-2 Weeks*
$61.35
RMA-23-SSV Flowmeter, range 5-50 LPM air. 1-3 days*
$62.40
RMB-51D Flowmeter, range 2-20 SCFH/1-9.5 LPM air. 1-2 Weeks*
$61.35
RMB-51D-SSV Flowmeter, range 2-20 SCFH/1-9.5 LPM air. 1-3 days*
$79.05
RMA-24-SSV Flowmeter, range 5-70 LPM air. 1-3 days*
$62.40
RMB-51-SSV Flowmeter, range 2-20 SCFH air. 1-3 days*
$79.05
RMB-52 Flowmeter, range 5-50 SCFH air. 1-3 days*
$61.35
RMA-25-SSV Flowmeter, range 10-100 LPM air. 1-3 days*
$62.40
RMB-52D Flowmeter, range 4-50 SCFH/2-23 LPM air. 1-2 Weeks*
$61.35
RMB-52D-SSV Flowmeter, range 4-50 SCFH/2-23 LPM air. 1-3 days*
$79.05
RMA-26-SSV Flowmeter, range .5-5 LPM air. 1-3 days*
$62.40
RMB-52-SSV Flowmeter, range 5-50 SCFH air. 1-3 days*
$79.05
RMB-53 Flowmeter, range 10-100 SCFH air. 1-2 Weeks*
$61.35
RMA-2-SSV Flowmeter, range .1-1 SCFH air. 1-3 days*
$62.40
RMB-53D Flowmeter, range 10-100 SCFH/5-50 LPM air. 1-2 Weeks*
$61.35
RMB-53D-SSV Flowmeter, range 10-100 SCFH/5-50 LPM air. 1-3 days*
$79.05
RMB-53-SSV Flowmeter, range 10-100 SCFH air. 1-3 days*
$79.05
RMA-32-SSV Flowmeter, range 5-50 cc/min water. 1-3 days*
$62.40
RMA-33-SSV Flowmeter, range 10-110 cc/min water. 1-2 Weeks*
$62.40
RMB-54 Flowmeter, range 20-200 SCFH air. 1-2 Weeks*
$61.35
RMA-34-SSV Flowmeter, range 20-300 cc/min water. 1-3 days*
$62.40
RMB-54D Flowmeter, range 20-200 SCFH/10-95 LPM air. 1-2 Weeks*
$61.35
RMA-3-SSV Flowmeter, range.2-2 SCFH air. 1-3 days*
$62.40
RMB-54D-SSV Flowmeter, range 20-200 SCFH/10-95 LPM air. 1-3 days*
$79.05
RMB-54-SSV Flowmeter, range 20-200 SCFH air. 1-3 days*
$79.05
RMA-4 Flowmeter, range .5-5 SCFH air, no valve. 1-3 days*
$47.05
RMB-55 Flowmeter, range 40-400 SCFH air. 1-2 Weeks*
$61.35
RMB-55-SSV Flowmeter, range 40-400 SCFH air. 1-3 days*
$79.05
RMA-42-SSV Flowmeter, range 1-11 GPH water. 1-3 days*
$62.40
RMB-56 Flowmeter, range 50-500 SCFH air. 1-2 Weeks*
$61.35
RMB-56-SSV Flowmeter, range 50-500 SCFH air. 1-3 days*
$79.05
RMA-43-SSV Flowmeter, range 2-24 GPH water. 1-3 days*
$62.40
RMB-57 Flowmeter, range 60-600 SCFH air. 1-2 Weeks*
$61.35
RMA-44 Flowmeter, range 4-34 GPH water, no valve. 1-2 Weeks*
$47.05
RMB-57-SSV Flowmeter, range 60-600 SCFH air. 1-3 days*
$79.05
RMA-44-SSV Flowmeter, range 4-34 GPH water. 1-2 Weeks*
$62.40
RMB-82 Flowmeter, range 1-12 GPH water. 1-2 Weeks*
$61.35
RMB-82D Flowmeter, range 1-12 GPH/0.06-0.76 LPM water. 1-2 Weeks*
$61.35
RMA-45-SSV Flowmeter, range 5-50 GPH water. 1-3 days*
$62.40
RMB-82D-SSV Flowmeter, range 1-12 GPH/0.06-0.76 LPM water. 1-3 days*
$79.05
RMA-4-SSV Flowmeter, range .5-5 SCFH air. 1-3 days*
$62.40
RMB-82-SSV Flowmeter, range 1-12 GPH water. 1-3 days*
$79.05
RMB-83 Flowmeter, range 1-20 GPH water. 1-2 Weeks*
$61.35
RMB-83D Flowmeter, range 1-20 GPH/0.065-1.25 LPM water. 1-2 Weeks*
$61.35
RMA-5-SSV Flowmeter, range 1-10 SCFH air. 1-3 days*
$62.40
RMB-83D-SSV Flowmeter, range 1-20 GPH/0.065-1.25 LPM water. 1-3 days*
$79.05
RMB-83-SSV Flowmeter, range 1-20 GPH water. 1-3 days*
$79.05
RMB-84 Flowmeter, range 4-40 GPH water. 1-2 Weeks*
$61.35
RMB-84-SSV Flowmeter, range 4-40 GPH water. 1-3 days*
$79.05
RMB-85 Flowmeter, range 10-100 GPH water. 1-2 Weeks*
$61.35
RMB-85D Flowmeter, range 10-100 GPH/0.8-6.2 LPM water. 1-2 Weeks*
$61.35
RMB-85D-SSV Flowmeter, range 10-100 GPH/0.8-6.2 LPM water. 1-3 days*
$79.05
RMB-85-SSV Flowmeter, range 10-100 GPH water. 1-3 days*
$79.05
RMC-101 Flowmeter, range 5-50 SCFH air. 1-2 Weeks*
$139.35
RMC-101-SSV Flowmeter, range 5-50 SCFH air. 1-3 days*
$191.35
RMC-102 Flowmeter, range 10-100 SCFH air. 1-2 Weeks*
$139.35
RMC-102-SSV Flowmeter, range 10-100 SCFH air. 1-3 days*
$191.35
RMC-103 Flowmeter, range 20-200 SCFH air. 1-2 Weeks*
$139.35
RMC-103-SSV Flowmeter, range 20-200 SCFH air. 1-2 Weeks*
$191.35
RMC-104 Flowmeter, range 40-400 SCFH air. 1-2 Weeks*
$139.35
RMC-104-SSV Flowmeter, range 40-400 SCFH air. 1-3 days*
$191.35
RMC-105 Flowmeter, range 60-600 SCFH air. 1-2 Weeks*
$139.35
RMC-105-SSV Flowmeter, range 60-600 SCFH air. 1-3 days*
$191.35
RMC-106 Flowmeter, range 100-1000 SCFH air. 1-2 Weeks*
$139.35
RMC-106-SSV Flowmeter, range 100-1000 SCFH air. 1-3 days*
$191.35
RMC-107 Flowmeter, range 120-1200 SCFH air. 1-2 Weeks*
$139.35
RMC-107-SSV Flowmeter, range 120-1200 SCFH air. 1-3 days*
$191.35
RMC-108 Flowmeter, range 200-1800 SCFH air. 1-3 days*
$139.35
RMC-108-SSV Flowmeter, range 200-1800 SCFH air. 1-3 days*
$191.35
RMC-121 Flowmeter, range 1-10 SCFM air. 1-3 days*
$139.35
RMC-121-SSV Flowmeter, range 1-10 SCFM air. 1-3 days*
$191.35
RMC-122 Flowmeter, range 2-20 SCFM air. 1-2 Weeks*
$139.35
RMC-122-SSV Flowmeter, range 2-20 SCFM air. 1-3 days*
$191.35
RMC-123 Flowmeter, range 3-30 SCFM air. 1-2 Weeks*
$139.35
RMC-123-SSV Flowmeter, range 3-30 SCFM air. 1-3 days*
$191.35
RMC-134 Flowmeter, range 2-20 GPH water. 1-2 Weeks*
$139.35
RMC-134-SSV Flowmeter, range 2-20 GPH water. 1-3 days*
$191.35
RMC-135 Flowmeter, range 8-90 GPH water. 1-2 Weeks*
$139.35
RMC-135-SSV Flowmeter, range 8-90 GPH water. 1-3 days*
$191.35
RMC-141 Flowmeter, range .1-1 GPM water. 1-2 Weeks*
$139.35
RMC-141-SSV Flowmeter, range .1-1 GPM water. 1-3 days*
$191.35
RMC-142 Flowmeter, range .2-2.2 GPM water. 1-2 Weeks*
$139.35
RMC-142-SSV Flowmeter, range .2-2.2 GPM water. 1-3 days*
$191.35
RMC-143 Flowmeter, range .4-4 GPM water. 1-2 Weeks*
$139.35
RMC-143-SSV Flowmeter, range .4-4 GPM water. 1-3 days*
$191.35
RMC-144 Flowmeter, range .8-7 GPM water. 1-2 Weeks*
$139.35
RMC-144-SSV Flowmeter, range .8-7 GPM water. 1-3 days*
$191.35
RMC-145 Flowmeter, range 1.2-10 GPM water. 1-2 Weeks*
$139.35
RMC-145-SSV Flowmeter, range 1.2-10 GPM water. 1-3 days*
$191.35

Specifications

Service:
Compatible gases and liquids.
Wetted Materials:
Body: Polycarbonate; O-ring: Neoprene and Buna-N; Metal parts: SS; Float: SS, black glass, aluminum, K monel, tungsten carbide depending on range.
Temperature Limit:
130°F (54°C).
Pressure Limit:
100 psi (6.9 bar).
Accuracy:
RMA: 4%; RMB: 3%; RMC: 2% of FS.
Process Connection:
RMA: 1/8"; RMB: 1/4"; RMC: 1/2" female NPT.
Weight:
RMA: 4 oz (113.4 g); RMB: 13 oz (368.5 g); RMC: 39 oz (1105.6 g).

Compliance:
Meets the technical requirements of EU Directive 2011/65/EU (RoHS II).
CAUTION:
Dwyer® Rate-Master® flowmeters are designed to provide satisfactory long term service when used with air, water, or other compatible media. Refer to factory for information on questionable gases or liquids. Caustic solutions, anti-freeze (ethylene glycol) and aromatic solvents should definitely not be used.

Features

  • Eliminate the need for troublesome conversions with direct reading scales
  • Reduce installation damage and cost due to stainless steel backbone that absorbs piping torque
  • Long operation life with durable, shatter-proof polycarbonate body
  • High repeatability enabled by precision injection molding around a precision tapered pin
  • Increased reading accuracy with special integral flow guides that stabilize float movement
  • Save time with instantaneous flow reading from scale graduations on both sides of the indicating tube

Options

  • Top Mounted Metering Valves - Same precision construction for vacuum applications RMA models only.
  • Adjustable Pointer Flags - Red lined pointer flags provide quick visual reference to a required flow level. Of clear plastic, they snap into place inside bezel and slide to desired level.
  • Specials - Special ranges, scales, mounting arrangements, etc., are available on special order, or in OEM quantities.

Product Literature

Manuals

Catalog Pages

Product Data Sheet

Approvals

Drawings

Model Chart

Series RMA - 2" Scale

EXAMPLE RMA 1 APF Series RMA-1-APF Rate-Master® Flowmeter, 2" Scale, range .05-.5 SCFH air, with adjustable pointer flag.
SERIES RMA     Rate-Master® Flowmeter, 2" Scale
RANGE   1
2
3
4
5
6
7
8
9
10
151
150
11
12
13
14
15
16
26
21
22
23
24
25
32
33
34
42
43
44
45		   .05-.5 SCFH Air
.1-1 SCFH Air
.2-2 SCFH Air
.5-5 SCFH Air
1-10 SCFH Air
2-20 SCFH Air
5-50 SCFH Air
10-100 SCFH Air
15-150 SCFH Air
20-200 SCFH Air
5-50 cc/min Air
10-100 cc/min Air
30-200 cc/min Air
50-500 cc/min Air
100-1000 cc/min Air
200-2500 cc/min Air
400-5000 cc/min Air
1000-10000 cc/min Air
.5-5 LPM Air
1-10 LPM Air
2- 25 LPM Air
5-50 LPM Air
5-70 LPM Air
10-100 LPM Air
5-50 cc/min Water
10-110 cc/min Water
20-300 cc/min Water
1-11 GPH Water
2-24 GPH Water
4-34 GPH Water
5-50 GPH Water
OPTIONS     APF
ARB
AT
BO
BOV
NIST
SPCL
SSV
TMV
VIT
WL		 Adjustable Pointer Flag
Arbitrary Scale (no units)
Aluminum Tag
Body Only
Body Only Valve Unit
NIST Traceable Calibration Certificate
Special Cleaning
Stainless Steel Valve
Top Mounted Valve
Fluoroelastomer O-rings
Without Logo


Series RMB - 5" Scale

EXAMPLE RMB 49 BPF Series RMB-49-BPF Rate-Master® Flowmeter, 5" Scale, range .5-5 SCFH air, with adjustable pointer flag.
SERIES RMB     Rate-Master® Flowmeter, 5 " Scale
RANGE   49
50
51
52
53
54
55
56
57
82
83
84
85
50D
51D
52D
53D
54D
82D
83D
85D		   .5-5 SCFH Air
1-10 SCFH Air
2-20 SCFH Air
5-50 SCFH Air
10-100 SCFH Air
20-200 SCFH Air
40-400 SCFH Air
50-500 SCFH Air
60-600 SCFH Air
1-12 GPH Water
1-20 GPH Water
4-40 GPH Water
10-100 GPH Water
1.2-10 SCFH & 0.6-5 LPM Air
3-20 SCFH & 1.5-9.5 LPM Air
4-50 SCFH & 2-23 LPM Air
10-100 SCFH & 5-50 LPM Air
20-200 SCFH & 10-95 LPM Air
1-12 GPH & 0.06-0.76 LPM Water
1-20 GPH & 0.065-1.25 LPM Water
10-100 GPH & 0.5-6.2 LPM Water
OPTIONS     ARB
AT
BO
BOV
BPF
NIST
SPCL
SSV
VIT
WL		 Arbitrary Scale (no units)
Aluminum Tag
Body Only
Body Only Valve Unit
Adjustable Pointer Flag
NIST Traceable Calibration Certificate
Special Cleaning
Stainless Steel Valve
Fluoroelastomer O-rings
Without Logo


Series RMC - 10" Scale

EXAMPLE RMC 101 CPF Series RMC-101-CPF Rate-Master® Flowmeter, 10" scale, range 5-50 SCFH air, with adjustable pointer flag.
SERIES RMC     Rate-Master® Flowmeter, 10" Scale
RANGE   101
102
103
104
105
106
107
108
121
122
123
134
135
141
142
143
144
145		   5-50 SCFH Air
10-100 SCFH Air
20-200 SCFH Air
40-400 SCFH Air
60-600 SCFH Air
100-1000 SCFH Air
120-1200 SCFH Air
200-1800 SCFH Air
1-10 SCFM Air
2-20 SCFM Air
3-30 SCFM Air
2-20 GPH Water
8-90 GPH Water
.1-1 GPM Water
.2-2.2 GPM Water
.4-4 GPM Water
.8-7 GPM Water
1.2-10 GPM Water
OPTIONS     ARB
AT
BO
BOV
NIST
CPF
SPCL
SSV
VIT
WL		 Arbitrary Scale (no units)
Aluminum Tag
Body Only
Body Only Valve Unit
NIST Traceable Calibration Certificate
Adjustable Pointer Flag
Special Cleaning
Stainless Steel Valve
Fluoroelastomer O-rings
Without Logo

Questions

Question
How are Dwyer flowmeters properly read?
Answer
The flow rate is read at the maximum width portion of the float regardless of shape.
Related
Series VFC/VFCII
Series VFC/VFCII
Series VF
Series VF
Series MM
Series MM
Series RM
Series RM
Question
I am looking to use an "Air" flowmeter RMA-6-SSV to monitor CO2 flow. I am wondering if there are are any concerns or correction factors I need to apply.
Answer
A specific gravity correction factor will need to be considered when monitoring other gases with a meter calibrated for air. The correction factor equation is as follows: Q2=Q1 x sqrt (1/S.G.) Where: Q1= Observed Flowmeter reading Q2= Standard Flow Corrected for Specific Gravity 1= Specific Gravity of Air or Water S.G.= Specific Gravity of media being used in flowmeter originally calibrated for air or water.
This equation can be found in the beginning of the Flow section in the catalog. Alternatively, special ranges and scales can be provided; for specific information please contact our technical service department.
Related
Series DR
Series DR
Series RM
Series RM
Series VF
Series VF
Series LFM
Series LFM
Series VFC/VFCII
Series VFC/VFCII
Series VA
Series VA
Question
Instruction Sheet specs on RM series flowmeters list 100 PSI max pressure, but have seen several RMC flowmeter labels with 35 PSI max pressure rating. Some clarification on pressure ratings please? Thank you.
Answer
The older version of the RMC used to have a pressure limit of 35psi because the back plate was assembled from 2 separate pieces. The pressure rating increased to 100psi when we began to stamp the back plate from 1 solid piece.
Related
Series RM
Series RM
Question
Where is the date code or lot number located on the flowmeter Model RMA-3-SSV?
Answer
The date code is on the label.
Related
Series RM
Series RM
Question
Are your flowmeters (particularly the brass body models) RoHS compliant? Can you provide a statement to that effect?
Answer
You can find the RoHS Compliance letter in the tab marked APPROVALS on RM Series.
Related
Series RM
Series RM
Question
For the VFA-44-BV product, what is the minimum flow that I can reliably control with a pressure head of up to 4 bar? Will the needle valve function properly at that pressure/flow combination? Thank you.
Answer
At a pressure of 4 bar (58 psi), the needle valve should function properly and provide reliable control over the whole range, which is 8-40 gallons of water per hour.
Related
Series VF
Series VF
Series RM
Series RM
Question
Is a Dwyer Certificate of Conformance offered with any of the flowmeter models?
Answer
A standard Dwyer Certificate of Conformance can be offered with all Dwyer Mini-Master®, Rate-Master®, and Visi-Float® flowmeters on all water ranges (or other compatible liquids).
Related
Series VFC/VFCII
Series VFC/VFCII
Series MM
Series MM
Series VF
Series VF
Series RM
Series RM
Question
Are special ranges available for the Rate-Master® and/or Visi-Float® Flowmeter?
Answer
Yes, other ranges are available which are not specified in our catalog. Please feel free to contact Dwyer with questions on these ranges.
Related
Series VFC/VFCII
Series VFC/VFCII
Series RM
Series RM
Series VF
Series VF
Question
Is the Rate-Master® or Visi-Float® Flowmeter compatible with any media?
Answer
The Rate-Master® Flowmeter is manufactured from a polycarbonate plastic and the Visi-Float® Flowmeter is manufactured from acrylic. Compatibility charts need to be reviewed to determine if these materials of construction are compatible with your media.
Related
Series VF
Series VF
Series RM
Series RM
Series VFC/VFCII
Series VFC/VFCII
Question
Why are top mounted valves recommended for flowmeters used for vacuum service?
Answer
To maintain atmospheric pressure in the indicating bore and therefore preserve accuracy; an inlet restriction would reduce pressure in the bore. This is essentially the opposite situation to outlet back-pressure in a pressure system which increases pressure in the bore and also affects accuracy. Remember that all standard Dwyer flowmeters are calibrated for standard atmospheric pressure and temperature in the bore.
Related
Series MM
Series MM
Series RM
Series RM
Question
What factor is used to correct for different flowmeter inlet pressure?
Answer
If the flowmeter is exhausting to atmosphere, no correction factor is needed. If back-pressure is present due to downstream plumbing or restrictions, this error can be corrected utilizing the conversion curves in our full-line catalog or the following equation.

Pressure: Q2 = Q1 x √((P1 x T2)/(P2 x T1))

Where:
Q1 = Observed Flowmeter Reading
Q2 = Standard Flow Corrected for Specific Gravity
P1 = Actual Pressure (14.7 psia + Gage Pressure)
P2 = Standard Pressure (14.7 psia, which is 0 psig)
T1 = Actual Temperature (460 R + Temp °F)
T2 = Standard Temperature (530 R, which is 70°F)
Related
Series RM
Series RM
Series VFC/VFCII
Series VFC/VFCII
Series MM
Series MM
Series VF
Series VF
Question
What is the calibration frequency, if required, for a RMB flowmeter?
Answer
Calibration frequency would be once a year if necessary. We offer a NIST calibration certificate which expires in one year. Contact Customer Service for additional details.
Related
Series RM
Series RM
Question
Which flowmeters are available with NIST traceability?
Answer
All Dwyer Mini-Master®, Rate-Master®, and Visi-Float® flowmeters are available with NIST traceability on all air ranges except for RMA-1, RMA-11, RMA-150, RMA-151, VFA-1, VFA-21 and VFB-60 models.
Related
Series VF
Series VF
Series MM
Series MM
Series VFC/VFCII
Series VFC/VFCII
Series RM
Series RM
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Model Description Availability* Price
RKA Regulator kit for RMA or VFA. 1-3 days*
$285.85
RK-RMB Regulator kit for RMB. 1-2 Weeks*
$285.85
100042-00 Optional pointer flag, for RMA flowmeter 1-3 days*
$9.05
100043-00 Optional pointer flag, for RMB flowmeter 1-3 days*
$9.55
100044-00 Optional pointer flag, for RMC flowmeter 1-3 days*
$9.55
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