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Building and Industry


Sensus HRI-Mei

HRI-Mei sensor reading device is a data interface for pulse output for industrial water meters. It provides a high-resolution pulse output with a flow direction signal. The data interface can be used for M-Bus applications. Designed for industrial water meters like MeiStream and MeiTwin, the HRI-Mei can be retrofitted without breaking your meter’s metrological seal. It is also built to withstand harsh environments, like flooded pits.



The HRI-Mei is a data capture device for MeiStream an MeiTwin MID bulk water meters. All MeiStream standard registers are prepared to receive the HRIMei. The HRI-Mei can also be mounted afterwards without breaking the meter’s seal. The HRI-Mei provides a high resolution pulse output with water flow direction detection. Also the data interface can be used for M-Bus applications. With the HRI-Mei all known data interfaces with Encoder, Electronic and Hybrid registers can be replaced. Depending on the register a second pulser like the Opto OD can be plugged in additionally e.g. at the MeiStream. Also other applications requiring reed switches or optical pulse outputs can be supported with only this one data capture device.

Sensus HRI-MEI

Special Features

  • Compatible to bulk water meters with MeiStream and MeiTwin MID standard register
  • Load-free inductive scanning of the meter’s pointer
  • Retrofitable
  • Detection of water flow direction
  • Electronic pulse output means no switch bouncing
  • Pulse-weight, mode and length can be changed on site
  • Self diagnostic and tamper detection
  • Battery lifetime up to 12 years. With external power supply i.e. a M-Bus central unit lifetime can be expanded
  • Sealed housing (IP68)
  • Cable length 3m

System Overview


Meter reading based for billing purposes i.e. mobile reading systems.

Meter remote reading and profiling via cable fixed networks with M-Bus, radio modem or GSM network.

Industrial control applications with the FM-1D/K or FM-2D/K

Data logging in conjunction with various data loggers; i.e. CDL.

Logging and transfer of flow profiles e. g. when using Waterbox internet access.

Robust design allows the use of the HRI-Mei in harsh environments like flooded pits.

Classical Sensus pulsers and equivalent HRI-Mei mode

Pulse Modes

The HRI-Mei provides 4 different pulse output modes via 2 lines. Parallel usage of the pulse output and serial output is not recommended and may cause problems depending on the application.

Mode B2:

I1: Forward pulses

I2: Backward pulses

Mode B3:

I1: For-/Backward pulses

I2: signal for the flow direction (1)

Mode B4 (default):

l1: balanced pulses (2)

l2: Alarm (opens when there is an alarm or cable cut) (3)

Mode B5:

Opto-OD (NAMUR) pulse output (6 ms)

I1: pulses with flow direction code

I2: not used

Temperature range:

HRI-Mei standard for cold water (30 °C) and warm water (50 °C).

Environmental temperature range: -10 °C ... +60 °C

(1) Ground level means reverse flow

(2) Backward pulses are compensated by suppressing the same quantity of forward pulses

(3) Alarms can be programmed for broken pipe, leakage, tampering, cable cut and indicated by ground level at the output

Technical Data

Pulse output

According to pulse mode

Opto-OD (NAMUR) compatible:

programmable pulse weights (10, 25,....1000) litre/pulse

Pulse length 6ms

NAMUR acc. EN 60947-5-6

Reed-RD compatible:

programmable pulse weights (10, 25,....10000) litre/pulse

Pulse length 32, 128 or 500ms

max. Voltage 48 Vdc

max. current 0,2 A

max. switching capacity 4 W

Data interface

M-Bus (autodetected)

Autom. detection of baud rate (300/2400Bd) and type of interface.

Data protocol according IEC870-5/EN1434-3

An Encoder mode provides an easy to use data protocol compatible to the encoder registers.

Transferred Data

Meter index

Fabrication number

Meter ID. equivalent to secondary address

Monthly meter index for programmable day

Meter index for programmable yearly key date and for the year before

Min./max. water flow with date/time

Backward water volume with date/time

Broken pipe and leakage detection with programmable flow thresholds

Tamper detection (*)

The HRI-Mei can be programmed to transfer selected information.

Programmable Data

All changeable data can be set with MiniCom software via the M-Bus / MiniBus data interface.

MiniCom download is free of charge from the Sensus web site.

(*) Requires tamper target at the meter.

Possible Pulse Values

PDF Datasheets

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Engineering Data*

2D CAD Drawing

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Engineering Data*
* Note: For some products Manual or Engineering Data are available only upon request.

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Product code

Sensus HRI-Mei

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