Product Overview
The ER-420 is the Industrial Oval Gear line’s scalable rate and flow counter — the simplest way to turn the oval-gear meter pulse into a control-system signal. It drives a programmable-scaled 4–20 mA flow-rate output plus a scaled pulse into a PLC, DCS or flow computer, and that is the whole job: no local display and no fieldbus, just the analog loop and the pulse. It comes in three power builds — AC (115–230 VAC), DC (24 VDC) and loop-powered — so it suits a panel feed, a 24 V supply or a bare current loop with no local power. It accepts coil sine-wave, reed and hall inputs and runs −22 to 176°F. When the point needs more than a 4–20 mA loop — a digital protocol, a local display, or a classified-area rating — the rest of the family covers it: the ER-500A and the F110D/E add Modbus RTU over RS-485, the F018 adds HART 7.0, and the intrinsically safe F-series variants carry the ATEX gas-and-dust marking.
Key Features & Benefits
- Scaled 4–20 mA from a pulse meter — it turns the oval-gear pulse into a programmable-scaled 4–20 mA flow-rate signal a control system can read directly
- Powered the way the install allows — AC, 24 VDC and loop-powered models cover a panel feed, a 24 V supply or a bare current loop with no local power
- Takes most pulse inputs — coil, reed and hall inputs let one counter serve the oval-gear meter and other pulse sources on the same skid
- Analog and pulse together — a scaled pulse rides alongside the 4–20 mA output for a totalizer downstream
- Remote or at the meter — mount it in a panel away from the process or right on the meter as the duty wants
Specifications
- Function
- A scalable rate / flow counter with a 4–20 mA output — it takes the oval-gear meter pulse and drives a scaled 4–20 mA flow-rate signal plus a scaled pulse to a PLC, DCS or flow computer. The F110 is its more-capable F-series counterpart (backlit display, optional RS-485, intrinsically safe variant)
- Models
- ER-420-AC (115–230 VAC), ER-420-DC (24 VDC) and ER-420-LP (loop-powered) — the power option is the model choice
- Signal inputs
- Turbine sine-wave (coil) pick-ups, reed switches, hall-effect sensors and other active or passive pulse sources
- Analog output
- Scaled 4–20 mA representing flow rate, with programmable scaling
- Pulse output
- Scaled pulse output
- Communication
- None on the ER-420 — it is the 4–20 mA counter. For Modbus RTU choose the ER-500A or the F110D/E (RS-485) F-series variant; for HART 7.0 choose the F018
- Power
- 115–230 VAC, 24 VDC, or two-wire loop-powered — by model
- Operating temperature
- −22 to 176°F (−30 to 80°C)
- Mounting
- Remote field-mount or meter-mounted
Common Applications
- Scaled 4–20 mA flow-rate signal from an oval-gear meter into a PLC or DCS
- Loop-powered 4–20 mA output where no local power reaches the counter
- Pulse-to-analog conversion feeding a control panel away from the process
- Scaled 4–20 mA and pulse on lubricant, fuel and chemical-additive dosing and batching skids
- Counting coil, reed or hall pulse sources alongside the oval-gear meter on one shared counter
Design & Selection Considerations
- Pick the power model to the install — a loop-powered ER-420-LP needs only the 4–20 mA loop and no local supply; the DC model wants a 24 VDC feed; the AC model takes line power. Use the input form to tell us the power available at the counter and we’ll pick AC, DC or loop-powered.
- The ER-420 is the 4–20 mA counter — if you need a protocol, step up the register — the ER-420 gives a scaled 4–20 mA and a scaled pulse, and nothing else — no display, no fieldbus. For a digital protocol, the choice is in the rest of the family: the ER-500A or the F110D/E variant of the F-series add Modbus RTU over RS-485, and the F018 adds HART 7.0. Use the input form to tell us the protocol and we’ll route you to the right register.
- Need a classified area or a local display? — move to the F-series — the ER-420 itself is not catalogued as an intrinsically safe build and carries no local display. For a hazardous area, the intrinsically safe F110B (and the ER-420’s F-series siblings) carry the ATEX Ex ia gas-and-dust marking; for a reading at the counter, the F110 adds a backlit display. Use the input form to tell us the area classification and whether you need a local display and we’ll pick the right variant.
To select the right ER-420 rate & flow counter:
Use the input form to tell us the meter it mounts on, the signal you need — a local display, a scaled pulse, a 4–20 mA loop, HART 7.0, Modbus RTU, an alarm contact or batch control — the power source and the area classification, and we’ll match the register or sensor to it.
Flow Meter Application Sheet ›Talk to an engineer directly — Scott Prater, Principal · 917-580-0878 · scott@pratertechnical.com
Specifications compiled by Prater Technical Partners from Badger Meter Industrial Oval Gear positive-displacement meter product literature.