Series RM Rate-Master® Polycarbonate Flowmeter
2", 5" or 10" Scale, Interchangeable Bodies*
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.
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.
DID YOU KNOW that you can add YOUR logo to our Rate-Master® flowmeter, call customer service for details.
*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.
Product Applications
- Medical equipment
- Air samplers
- Gas analyzers
- Pollution monitors
- Chemical injectors
- Cabinet purging
Models & Ordering
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).
- Agency Approvals:
- 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.
Accessories
| Model Number | Description | Usually Ships* | Price | Order | |
|---|---|---|---|---|---|
 |
RKA | Regulator kit for RMA or VFA. | Next Day | $250.00 | Order |
|
RK-RMB | Regulator kit for RMB. | 1-2 Weeks | $250.00 | Order |
 |
100042-00 | Optional pointer flag, for RMA flowmeter. | Next Day | $7.50 | Order |
 |
100043-00 | Optional pointer flag, for RMB flowmeter. | Next Day | $8.00 | Order |
|
100044-00 | Optional pointer flag, for RMC flowmeter. | Next Day | $8.00 | Order |
Videos
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 |
Product Literature
Manuals
Catalog Pages
Product Data Sheet
Approvals
Drawings
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.
- 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 customer service department.
For further information, see our "Tech & Specs" Video Blog: Fix your Flow... Specific Gravity and Pressure Corrections for Variable Area Flowmeters (Episode 4), in Dwyer's Video Library.
- 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 backplate was assembled from 2 seperate pieces. The pressure rating increased to 100psi when we began to stamp the backplate from 1 solid piece.
- 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.
- 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.
- 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.
- 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).
- 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.
- 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.
- 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.
- 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)
- 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 at 800-872-9141 Ext. 656 for current cost.
- 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.
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