FM Approvals Canadian Standards Association Atmosphères Explosibles European Conformity
The ProtEX-MAX™ PD8-6363 offers all the functionality of the ProVu PD6363 as a fully FM, CSA, ATEX, and IECEx approved explosion-proof product. It is specifically designed to display flow rate and total from two (2) pulse output (NPN, PNP, TTL, switch contact, sine wave, etc.) flowmeters. It displays these signals on a dual-line, 6-digit Sunbright sunlight readable display. The two display lines can be used to show both flow rates simultaneously, to alternate between the two inputs showing both the flow rate and total of each, or to show the result of math functions performed on the flow rates and totals. The total overflow feature allows up to 9-digit totals and grand totals to be displayed. The PD8-6363 includes a 24 VDC power supply to drive the flowmeter and can be equipped with up to four internal relays and a 4-20 mA analog output. It can be programmed and operated without opening the housing by using the built-in SafeTouch® through-glass buttons or the RS485 serial communication port with free Modbus® protocol.

MeterView Pro USB Install    MeterView Pro USB Install

Quick Overview

  • Input: Two pulse inputs, each separately field selectable; open collector, NPN, PNP, TTL, switch contact, sine wave (coil), square wave; Modbus PV (slave)
  • Display: Dual-line 6-digit, 0.60" (15 mm) & 0.46" (12 mm)
  • Case: Smooth die-cast aluminum explosion-proof
  • Power: 85-265 VAC or 12-24 VDC option
  • Operating Temperature: -40 to 65°C


  • SunBright Display Standard
  • Rate, Total, and Grand Total for Each Input Channel
  • Addition, difference, absolute difference, average, multiplication, division, min of A or B, max of A or B, draw, weighted average, and ratio math functions including total and grand total math
  • Gate function for rate display of slow pulse rates
  • 4-20 mA output option converts the pulse input to an isolated 4-20 mA output
  • SafeTouch® through-glass button programming
  • Modbus RS-485 serial communications
  • Flanges for wall or pipe mounting
  • Isolated 24 VDC @ 25 mA transmitter power supply
  • Onboard USB and MeterView® Pro programming software


Display: Upper display: 0.60" (15 mm) high. Lower display: 0.46" (12 mm) high. 6 digits each (-99999 to 999999), red LEDs with lead zero blanking.
Display Intensity: Eight user selectable intensity levels
Display Update Rate: 10 per second; up to 1 per 100 seconds (and is a function of Low Gate setting); Total: 10 per second (fixed)
Overrange: Display flashes 999999
Underrange: Display flashes -99999
Display Assignment: The Upper and Lower displays may be assigned to show: One or more rate channels: Channel A (Ch-A), B (Ch-B), or C (Ch-C), Toggle between rate channels: Ch-A & Ch-B, Ch-A & Ch-C, Ch-B & Ch-C, and Ch-A, Ch-B, & Ch-C, Total or grand total: Ch-A or Ch-B, Rate and total or grand total: Ch-A, Ch-B, Relay set points, Max and/or min values: Ch-A, Ch-B, or Ch-C, Toggle between any rate channel & units, Toggle between any rate/math channel & units, Total and units: Ch-A or Ch-B, Toggle between totals: Ch-A & Ch-B; Ch-A, Ch-B, and sum of Ch-A and Ch-B, Modbus input. The lower display may also be set to show engineering units or be off, with no display.
Programming Methods: Four through-glass SafeTouch buttons, four mechanical buttons behind glass, digital inputs, PC and MeterView Pro software, or Modbus registers.
F4 Digital Input Contacts: 3.3 VDC on contact. Connect normally open contacts across F4 to COM.
F4 Digital Input Logic Levels: Logic High: 3 to 5 VDC; Logic Low: 0 to 1.25 VDC
Max/Min Display: Max/min readings reached by the process are stored until reset by the user or until power to the meter is cycled.
Password: Three programmable passwords restrict modification of programmed settings and two prevent resetting the totals.
   Pass 1: Allows use of function keys and digital inputs
   Pass 2: Allows use of function keys, digital inputs and editing set/reset points
   Pass 3: Restricts all programming, function keys, and digital inputs.
   Total: Prevents resetting the total manually
   Gtotal: Prevents resetting the grand total manually
Non-Volatile Memory: All programmed settings are stored in non-volatile memory for a minimum of ten years if power is lost.
Recalibration: All ranges are calibrated at the factory. Recalibration is recommended at least every 12 months.
Power Options: 85-265 VAC 50/60 Hz, 90-265 VDC, 20 W max, or optional model with 12-24 VDC ±10%, 15 W max.
Fuse: Required external fuse: UL Recognized, 5 A max, slow blow; up to 6 meters may share one 5 A fuse.
Isolated Transmitter Power Supply: Terminals P+ & P-: 24 VDC ± 10%. Isolated from the input at >500 V. Jumper selectable for 24, 10, or 5 VDC supply (internal jumper J4). All models transmitter supply rated @ 25mA max.
Isolation: 4 kV input/output-to-power line. 500 V input-to-output or output-to-P+ supply.
Overvoltage Category: Installation Overvoltage Category II: Local level with smaller transient overvoltages than Installation Overvoltage Category III.
T6 Class operating temperature range Ta = -40 to 60°C
T5 Class operating temperature range Ta = -40 to 65°C
Max Power Dissipation: Maximum power dissipation limited to 15.1 W.
Connections: Removable screw terminal blocks accept 12 to 22 AWG wire, RJ45 for external relays, digital I/O, and serial communication adapters.
Enclosure: Explosion-proof die cast aluminum with glass window, corrosion resistant epoxy coating, color: blue. NEMA 4X, 7, & 9, IP68. Default conduit connections: Four ¾" NPT threaded conduit openings and two ¾" NPT metal conduit plugs with 12 mm hex key fitting installed. Additional conduit opening configurations may be available; verify quantity and sizes on specific device labeling during installation.
Mounting: Four slotted flanges for wall mounting or NPS 1½" to 2½" or DN 40 to 65 mm pipe mounting
Dimensions: 6.42" x 7.97" x 8.47" (W x H x D) (163 mm x 202 mm x 215 mm)
Weight: 16.0 lbs (7.26 kg)
Warranty: 3 years parts & labor
USB Connection: Compatibility: USB 2.0 Standard, Compliant
   Connector Type: Micro-B receptacle
   Cable: USB A Male to Micro-B Cable
   Driver: Windows 98/SE, ME, 2000, Server 2003/2008, XP 32/64-Bit,
   Vista 32/64-Bit, Windows 7 32/64-Bit, Windows 10 32/64-Bit
   Power: USB Port

Dual Input Functionality

Pulse Inputs: Two, Field selectable: Pulse or square wave 0-5 V, 0-12 V, or 0-24 V @ 30 kHz; TTL; open collector 4.7 kΩ pull-up to 5 V @ 30 kHz; NPN or PNP transistor, switch contact 4.7Ω kpull-up to 5 V @ 40 Hz; Modbus PV (Slave) Channels: Channel A, Channel B, Channel C (Math channel)
Programmable Constants: Constant P (Adder): -99.999 to 999.999, default: 0.000, Constant F (Factor): 0.001 to 999.999, default: 1.000
Sequence of Operations for Input Programming:
   1.  Select Input for A and B
   2.  Set up the rate, total, and grand total engineering units for channels A & B, and units for math channel C
   3.  Set up rate, total, and grand total decimal points for channels A & B, and decimal point for math channel C
   4.  Program channel A & B rate parameters
   5.  Program channel A & B total and reset parameters
   6.  Set up the big and little displays and display intensity
   7.  Select the transfer function for A & B (e.g. Linear)
   8.  Select Math function for Channel C
   9.  Program constants for Factor (F) and Adder (P)
   10. Program cutoff values for A and B
Low Voltage Mag Pickup: Sensitivity: 40 mVp-p to 8Vp-p
Minimum Input Frequency: 0.001 Hz Minimum frequency is dependent on high gate setting.
Maximum Input Frequency: 30,000 Hz (10,000 for low voltage mag pickup)
Accuracy: ±0.03% of calibrated span ±1 count
Temperature Drift: 0.005% of calibrated span/°,C max from 0 to 65°C ambient, 0.01% of calibrated span/°C max from -40 to 07°C ambient Rate display is not affected by changes in temperature.
Multi-Point Linearization: 2 to 32 points for channel A and B
Low-Flow Cutoff: 0-999999 (0 disables cutoff function)
Decimal Point: Up to five decimal places or none: d.ddddd, dd.dddd, ddd.ddd, dddd.dd, ddddd.d, or dddddd.
Calibration Range: Input 1 signal may be set anywhere in the range of the meter; input 2 signal may be set anywhere above or below input 1 setting. Minimum input span between any two inputs is 10 Hz. An error message will appear if the input span is too small.
Calibration: May be calibrated using K-factor, internal calibration, or by applying an external calibration signal.
K-Factor: Field programmable K-factor converts input pulses to rate in engineering units. May be programmed from 0.00001 to 999,999 pulses/unit.
Filter: Programmable contact de-bounce filter: 40 to 999 Hz maximum input frequency allowed with low speed filter.
Time Base: Second, minute, hour, or day
Gate: Low gate: 0.1-99.9 seconds, High gate: 2.0-999.9 seconds
F4 Digital Input Contacts: 3.3 VDC on contact. Connect normally open contacts across F4 to COM.
F4 Digital Input Logic Levels: Logic High: 3 to 5 VDC, Logic Low: 0 to 1.25 VDC

Dual Rate/Totalizer

Rate Display Indication: 0 to 999999, lead zero blanking.
Total Display & Total Overflow: 0 to 999,999; automatic lead zero blanking. Up to 999,999,999 with total-overflow feature. "oF in 7-Segment Font" is displayed to the left of total overflow.
Total Decimal Point: Up to five decimal places or none: d.ddddd, dd.dddd, ddd.ddd, dddd.dd, ddddd.d, or dddddd. Total decimal point is independent of rate decimal point. Channel A and B decimal points programmed independently.
Dual Totalizer: Calculates total for channels A and B based on rate and field programmable multiplier to display total in engineering units. Time base must be selected according to the time units in which the rate is displayed. Channel A and B totalizer parameters programmed independently.
Totalizer Rollover: Totalizer rolls over when display exceeds 999,999,999. Relay status reflects the display value.
Total Overflow Override: Program total A or B total reset for automatic with 0.1 second delay and set point 1 for 999,999
Totalizer Alarm Presets: Up to eight, user selectable under setup menu. Any set point can be assigned to channel A or B total or grand total (or C) and may be programmed anywhere in the range of the meter for total alarm indication.
Total & Grand Total Reset: Via front panel button, external contact closure on digital inputs, automatically via user selectable preset value and time delay, or through serial communications. Channel A and B total and grand total reset parameters programmed independently.
Total Reset Password: Total and grand total passwords may be entered to prevent resetting the total or grand total from the front panel.
Non-Resettable Total: The grand totals can be programmed as non-resettable totals by entering the password "050873". Both channels are set to non-resettable when this password is entered. Caution: Once the Grand Total has been programmed as "non-resettable" the feature cannot be disabled.
Programmable Delay on Release: 0.1 and 999.9 seconds; applied to the first relay assigned to total or grand total. If the meter is programmed to reset total to zero automatically when the preset is reached, then a delay will occur before the total is reset.


Rating: 2 or 4 SPDT (Form C) internal and/or 4 SPST (Form A) external; rated 3 A @ 30 VDC and 125/250 VAC resistive load; 1/14 HP (≈ 50 W) @ 125/250 VAC for inductive loads
Noise Suppression: Noise suppression is recommended for each relay contact switching inductive loads.
Relay Assignment: Relays may be assigned to channel A or B rate, total, or grand total; channel C; or Modbus control.
Deadband: 0-100% of span, user programmable
High or Low Alarm: User may program any alarm for high or low trip point. Unused alarm LEDs and relays may be disabled (turned off).
Relay Operation: automatic (non-latching), latching (requires manual acknowledge), sampling (based on time), pump alternation control (2 to 8 relays), off (disable unused relays), and manual on/off control mode.
Relay Reset: User selectable via front panel buttons, digital inputs, or PC
   1. Automatic reset only (non-latching), when input passes the reset point.
   2. Automatic + manual reset at any time (non-latching).
   3. Manual reset only, at any time (latching).
   4. Manual reset only after alarm condition has cleared (latching).
Note: Front panel button or digital input may be assigned to acknowledge relays programmed for manual reset.
Time Delay: 0 to 999.9 seconds, on & off relay time delays. Programmable and independent for each relay.
Fail-Safe Operation: Programmable and independent for each relay.
Note: Relay coil is energized in non-alarm condition. In case of power failure, relay will go to alarm state.
Auto Initialization: When power is applied to the meter, relays will reflect the state of the input to the meter.

Isolated 4-20 mA Transmitter Output

Output Source: Input channels A or B, rate, total, or grand total; channel C; max or min for channel A or B; highest or lowest max or min of A and B; set points 1-8; Modbus input; or manual control mode.
Scaling Range: 1.000 to 23.000 mA for any display range
Calibration: Factory calibrated: 4.000 to 20.000 = 4-20 mA output
Analog Output Programming: 23.000 mA maximum for all parameters: Overrange, underrange, max, min, and break
Accuracy: ±0.1% FS ±0.004 mA
Temperature Drift: 0.4 µA/°C max from 0 to 65°C ambient, 0.8 µA/°C max from -40 to 0°C ambient
Note: Analog output drift is separate from input drift.
Isolated Transmitter Power Supply: Terminals I+ & R: 24 VDC ± 10%. Isolated from the input at >500 V. May be used to power the 4-20 mA output or other devices. All models @ 25 mA max.
External Loop Power Supply: 35 VDC maximum
Output Loop Resistance:
      Power supply Minimum Maximum
      24 VDC 10Ω 700Ω
      35 VDC (external) 100Ω 1200Ω

Serial Communications

Compatability: EIA-485
Connectors: Removable screw terminal connector
Max Distance: 3,937' (1,200 m) max
Status Indication: Separate LEDs for Power (P), Transmit (TX), and Receive (RX)
Protocol: Modbus® RTU
Meter Address/Slave ID: 1 - 247
Baud Rate: 300 - 19,200 bps
Transmit Time Delay: Programmable between 0 and 199 ms
Data: 8 bit (1 start bit, 1 or 2 stop bits)
Parity: Even, odd, or none with 1 or 2 stop bits
Byte-to-Byte Timeout: 0.01 - 2.54 seconds
Turn Around Delay: Less than 2 ms (fixed)

Digital Inputs and Outputs

Channels: 4 digital inputs & 4 digital outputs per module
System: One expansion module may be added for a total of 8 inputs & 8 outputs
Note: The jumper located between the RJ45 connectors must be removed on the expansion module.
Digital Input Logic: High: 3 to 5 VDC; Low: 0 to 1.25 VDC
Digital Output Logic: High: 3.1 to 3.3 VDC; Low: 0 to 0.4 VD
Source Current: 10 mA maximum output current
Sink Current: 1.5 mA minimum input current
+5 V Terminal: To be used as pull-up for digital inputs only. Connect normally open pushbuttons across +5 V & DI 1-4. Warning: DO NOT use +5 V terminal (pin 1) to power external devices.
Function Assignment: The on-board digital inputs (1-4) are designed to mimic the behavior of the front panel buttons (Menu, F1, F2, & F3). If you wish to change their behavior, re-assign F1-F3 to the desired function, then change the corresponding digital input to match.

4-Relay Expansion Module

Relays: Four Form A (SPST) rated 3 A @ 30 VDC and 125/250 VAC resistive load; 1/14 HP (≈ 50 watts) @ 125/250 VAC for inductive loads.

Dual Analog Output Expansion Module

Outputs: Two passive 4-20 mA analog outputs
Scaling Range: 3.000 to 23.000 mA for any display range

Product Ratings and Approvals

FM Enclosure: Type 4X; IP66
   Class I, Division 1, Groups B, C, D
   Class II, Division 1, Groups E, F, G
   Class III, Division 1, T5/T6
   Class I, Zone 1, AEx d, IIC Gb T5/T6
   Zone 21, AEx tb IIIC T90°C; Ta -40°C to +65°C
   T6 Ta = -40°C to +60°C; T5 Ta = -40°C to +65°C
   Certificate Number: 3047283
CSA: Class I, Division 1, Groups B, C, D
   Class II, Division 1, Groups E, F, G
   Class III, Division 1
   Class I Zone 1 Ex d IIC
   Zone 21 Ex tb IIIC T90°C
   -40°C < Tamb. < +60° C; Temperature Code T6
   -40°C < Tamb. < +65° C; Temperature Code T5
   Enclosure Type 4X & IP66
   Certificate Number: 2531731
ATEX: II 2 G D    Ex d IIC T* Gb
   Ex tb IIIC T90°C Db IP68
   Ta = -40°C to +*°C
   *T6 = -40°C to +60°C
   *T5 = -40°C to +65°C
   Certificate number: Sira 12ATEX1182
IECEx: Ex d IIC T* Gb
   Ex tb IIIC T90°C Db IP68
   Ta = -40°C to +*°C
   *T6 = -40°C to +60°C
   *T5 = -40°C to +65°C
   Certificate Number: IECEx SIR 12.0073


Differential Pressure Flow (PD6262)

The PD8-6262 can display flow rate and total by extracting the square root from the 4-20 mA signal from differential pressure transmitters. The user selectable low-flow cutoff feature gives a reading of zero when the flow rates drop below a user selectable value.

  • Display Flow Rate
  • User Selectable Low-Flow Cutoff
  • Only 2 Calibration Points Required

Open Channel Flow (PD6262)

The PD8-6262, in combination with ultrasonic level transmitters, makes for an easy and convenient way to measure and display open channel flow rates and totals in most weirs and flumes, and take periodic samples. All the user needs to do is enter the exponents for the weirs or flumes into the PD8-6262 and the PD8-6262 automatically raises the input signals to those powers. Sampling can be based on the total flow or the flow rate. Each channel's signal input conditioning is programmed independently.

Weir Flow Calculated Using Exponential Signal Input Conditioning

Convert Pulse to 4-20 mA (PD6363)

The PD8-6363 accepts pulse outputs from flowmeters and with the appropriate option installed, can convert the pulses to a 4-20 mA signal. The 4-20 mA signal can be programmed to correspond to either the flow rate or the total flow.

  • Use K-Factor or Multi-Point Scaling
  • ProVu Powers the Flowmeter
  • Up to 3 Analog Outputs

MeterView® Pro Software

MeterView Pro Video MeterView® Pro software is designed for use with ProVu, ProtEX-MAX, or Helios Series meters and allows users to remotely program, monitor, and datalog using a PC. Remote programming allows for all available meter settings to be programmed through an easy, user-friendly interface. The data acquisition feature allows the user to gather readings from a meter at user-selected intervals and generate charts using common tools like Microsoft® Excel. A linearization setup function is also included. With this utility the user can configure up to 32 linearization points and upload them to the meter. All configuration data can be saved to a file for future use.
This software is accessible via the onboard USB connection on all Helios large display meters, ProVu panel meters, and ProVu-based ProtEX-MAX explosion-proof meters produced since 6 September 2016 (firmware version 4.0 or higher). In order for meters produced prior to 6 September 2016 (firmware version 3.1 or lower) to establish digital communications with a PC, a serial communications adapter is required. For an RS-232 connection, use a PDA1232 adapter.
To determine the software version of a meter:
  1. Go to the Diagnostics menu () and press Enter button.
  2. Press Up arrow button and scroll to Information menu (Info).
  3. Press Enter to access the software number (), version (), and serial number () information. Write down the information as it is displayed. Continue pressing Enter until all the information is displayed.
  4. The meter returns to Run Mode after displaying all the settings.
Click here for more information about MeterView Pro.
Click here to watch and introductory video on MeterView Pro.

Monitor and Datalog

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