Aluminum or Stainless Steel
Canadian Standards Association Atmosphères ExplosiblesEuropean ConformityIECEx Approval


  • Fully-Approved Explosion-Proof Loop-Powered Meter
  • 4-20 mA Input with ±0.03% Accuracy
  • 3.0 Volt Drop (6.0 Volt Drop with Backlight)
  • Easy Field Scaling in Engineering Units without Applying an Input
  • 0.6" (15.2 mm) Feet & Inches Main Display With 1/8 or 1/16 Resolution
  • 0.4" (10.2 mm) 7 Alphanumeric Characters Secondary Display for Tag, Volume, or Percent
  • Display Level in Feet & Inches and Volume, Percent or Decimal Height Simultaneously
  • Display Mountable at 0°, 90°, 180°, & 270°
  • SafeTouch Through-Glass Button Programming
  • 20-Segment Tank Side Level Indicator Bargraph
  • Open Collector Output Assignable to High or Low Alarm
  • HART® Protocol Transparent
  • Loop or External DC-Powered Backlight Standard
  • Operating Temperature Range: -40 to 75°C (-40 to 167°F)
  • Installation Temperature Range: -55 to 75°C (-67 to 167°F)
  • CSA Certified as Explosion-Proof / Dust-Ignition-Proof / Flame-Proof
  • ATEX and IECEx Certified as Explosion-Proof
  • Conformal Coated PCBs for Dust and Humidity Protection
  • Password Protection
  • 32-Point Linearization
  • Wide Viewing Angle
  • Built-In Flange for Wall or Pipe Mounting
  • Explosion-Proof, IP68, NEMA 4X Die-Cast Aluminum & Stainless Steel Enclosures
  • Two 3/4" NPT or M20 Conduit Openings
  • 2" U-Bolt Kit Available
  • 3-Year Warranty

Why Use Loop-Powered Meters?

The most basic decision a user wishing to display a 4-20 mA signal on a digital display has to make is: should the meter be powered by line voltage or should it be powered by the 4-20 mA loop?

There are three main benefits of using loop-powered devices:

  • No additional power required
  • Easy wiring
  • Additional digital displays can easily be added in the same loop

The following diagram illustrates how a loop-powered meter is wired. Notice there are only two connections made to the meter.

Loop-Powered Connections

For more information on loop-powered meters, check out Fundamentals of Loop-Powered Devices and Loop-Powered vs Line-Powered Meters white papers.


Hazardous Area F&I Loop-Powered Meter

The PD6801 is a rugged, full-featured, explosion-proof loop-powered meter specifically designed for level applications in hazardous areas or in the harshest environmental conditions. Instead of the usual decimal display, the meter displays level in feet, inches, and fractions of an inch with a 20-segment tank level indicator. The secondary display can show a custom unit or tag, percent full, or a second scale for the 4-20 mA input used to indicate volume. The backlight feature makes the display visible under any lighting condition and can be powered from either the 4-20 mA loop or from a separate DC power supply.

The product is CSA Certified as Explosion-Proof, Dust-Ignition-Proof, and Flame-Proof, and ATEX & IECEx Certified as Explosion-Proof. It is available in either an aluminum or stainless steel enclosure with ¾" or M20 conduit connections. It will operate down to -40°C and is approved for installation in areas where the temperature gets as cold as -55°C, however, the display will cease functioning.

The meter derives all of its power from the 4-20 mA loop thus making installation a simple matter of wiring the instrument into the existing loop. No external power is required. Programming is performed using the four SafeTouch through-glass buttons and can be done without removing the cover. In addition, the meter can be scaled with or without a calibration signal.

Except where noted all specifications apply to operation at +25°C.


DisplayFeet & Inches0.60" (15.2 mm) high
0 to 699FT 11 15/16IN
7-segment, programmable
1/16 or 1/8 fraction display
Seven characters
(Tag &/or Volume)
0.4" (10.2 mm) high 14-segment, 7-digits
Tank Level Indicator20-segments
Display OrientationDisplay may be mounted at 90° increments up to 270° from default orientation.
Display AssignmentUpper display: Feet & inches
Lower display may be assigned to custom unit or tag, volume, volume and tag, percent height, percent height and tag, or off.
Display Update Rate

Ambient > -25°C: 2 Updates/Second
Ambient < -25°C: 1 Update/5 Seconds

BacklightWhite; Loop-powered or externally powered. Backlight can be enabled or disabled via alternative wiring of terminal block.
Loop-powered backlight brightness will increase as the input signal current increases. Externally powered backlight has consistent brightness.
Externally Powered
Voltage Range: 9-36 VDC
Supply V  9 VDC  12 VDC  24 VDC  36 VDC
Max Pwr  0.2 W  0.25 W  0.5 W  0.75 W
Display Overrange and UnderrangeLevel display flashes to 699FT 11 15/16IN
Volume display flashes 9999999 if overrange, -999999 if underrange.
Programming MethodFour SafeTouch through-glass buttons when cover is installed. Four internal pushbuttons when cover is removed.
Noise FilterProgrammable low (LO), medium (MED), high (HI), or off (OFF)
RecalibrationRecalibration is recommended at least every 12 months.
Max/Min DisplayMax/Min readings reached by the process are stored until reset by the user or until power to the meter is turned off.
Advanced FunctionLinear, square root, or programmable exponent
PasswordProgrammable password restricts modification of programmed settings.
Non-Volatile MemoryAll programmed settings are stored in non-volatile memory for a minimum of ten years if power is lost.
Normal Mode Rejection64 dB at 50/60 Hz
EnvironmentalOperating temperature range: -40 to 75°C (-40 to 167°F)
Storage temperature range: -55 to 75°C (-67 to 167°F)
Installation temperature range: -55 to 75°C (-67 to 167°F)
(The display ceases to function below -40°C)
Relative humidity: 0 to 90% non-condensing
Printed circuit boards are conformally coated
ConnectionsScrew terminals accept 12 to 22 AWG wire
MountingMay be mounted directly to conduit. Built-in flange for wall mounting or NPS 1½" to 2½" or DN 40 to 65 mm pipe mounting.
Overall Dimensions5.65" x 5.25" x 4.86"
(W x H x D)
(144 mm x 133 mm x 124 mm)
WeightAluminum: 4.8 lbs (2.18 kg)
Stainless Steel: 8.7 lbs (4.3 kg)
Warranty3 years parts and labor. See Warranty Information and Terms & Conditions on for complete details.


Input4-20 mA
Accuracy±0.03% of calibrated span ±1 count
Maximum Voltage Drop & Equivalent ResistanceWithout Backlight or with
Externally Powered Backlight
With Loop-Powered Backlight
3.0 VDC @ 20 mA6.0 VDC @ 20 mA
150 Ω @ 20 mA300 Ω @ 20 mA
Temperature Drift50 PPM/°C from -40 to 75°C ambient
Multi-Point Linearization2 to 32 points, level and volume independently programmed.
Minimum SpanInput 1 & Input 2: 0.10 mA
Calibration RangeAn Error message will appear if input 1 and input 2 signals are too close together.
Input Range
4-20 mA
Minimum Span Input 1 & Input 2
0.10 mA
Input OverloadOver current protection to 2 A max.
HART TransparencyThe meter does not interfere with existing HART communications; it displays the 4 20 mA primary variable and it allows the HART communications to pass through without interruption.
The meter is not affected if a HART communicator is connected to the loop.
The meter does not display secondary HART variables.

Open Collector Output

RatingIsolated open collector, sinking NPN 30 VDC @ 150 mA max.
Alarm OutputAssign to level or volume for high or low alarm trip point.
Deadband0-100% FS, user selectable
AcknowledgeFront panel ENTER button and external RESET terminals resets output and screen indication.


MaterialAL Models: ASTM A413 LM6 die-cast aluminum, copper-free, enamel coated
SS Models: ASTM A743 CF8M investment-cast 316 stainless steel
Gasket (O-Ring)Fluoroelastomer
RatingNEMA 4X, IP68 Explosion-proof
ColorAL: Blue
SS: Silver
WindowBorosilicate glass
ConduitsPD6801-0K1: Two 3/4" NPT
PD6801-0K1-M20: Two M20
PD6801-0K1-SS: Two 3/4" NPT
PD6801-0K1-SS-M20: Two M20
FlangeBuilt-in flange for wall and pipe mounting.
Tamper-Proof SealCover may be secured with tamper-proof seal
Instrument Tag LoopBuilt-in loop for securing stainless steel tag
ATEX & IECExFlameproof protection
Ex db IIC Gb
Ex tb IIIC Db
Tamb: -55°C to +85°C
Certificate No.: Sira 19ATEX1252U
Certificate No.: IECEx SIR 19.0075U
CSAClass I, Division 1, Groups A, B, C, D
Class II, Division 1, Group E, F, G
Class III
Ex db IIC Gb
Ex tb IIIC Db
Class I, Zone 1, AEx db IIC Gb;
Zone 21, AEx tb IIIC Db
Tamb: -55°C to +85°C
Certificate Number: CSA 19.80011200U
ULClass I, Division 1, Groups A, B, C, D
Class II, Division 1, Groups E, F, G
Class III;
Class I, Zone 1, AEx db IIC Gb
Zone 21, AEx tb IIIC
Ex db IIC Gb
Ex tb IIIC Db
Tamb: -55°C to +85°C
Certificate Number: E518920
Note: The above approvals are for the enclosure only. See below for approval on the entire instrument.

Product Ratings & Approvals

Explosion-proof for use in:
Class I, Division 1, Groups B, C and D
Dust-ignition-proof for use in:
Class II/III, Division 1, Groups E, F and G; T6
Flame-proof for use in:
Zone 1, Ex d IIC T6
Ta = -55 to 75°C
Enclosure: Type 4X & IP66/IP68
Certificate Number: CSA 11 2325749
ATEXExplosion-proof for use in:
Ex db IIC T6 Gb
Ex tb IIIC T85°C Db IP68
Ta = -55 to 75°C
Certificate Number: Sira 10ATEX1116X
IECExExplosion-proof for use in:
Ex db IIC T6 Gb
Ex tb IIIC T85°C Db IP68
Ta = -55 to 75°C
Certificate Number: IECEx SIR 10.0056X



Front View
Side View
Top View

Choose Your Options

Configurations other than those specified above are available at a $250 adder. Consult factory for desired model number and price.