Mark Series  Position Indicators/Switches/Transmitters

The Proximity Mark Series is a line of position indicators with a selection of various output options. Four model styles make up the Mark series to cover almost any application. Standard models in the Mark Series have visual position indicators and are weatherproof, explosion-proof, and submersible. A large variety of outputs are available to fit specific applications. There is a choice of 1 to 6 switch outputs of 16 varieties including inductive sensors, high temperature switches, gold contact switches, hermetically sealed switches, and high current switches. Besides the switch outputs, the Series offers potentiometer outputs and 4 to 20 mA transmitters. The units are purchased for either direct drive applications, such as rotary valves, or lever drive applications, such as linear valves. Adjustable visual indicator is standard on direct drive units that displays OPEN/CLOSED status and degrees.

A patented magnetic drive that completely seals the switch compartment from the atmosphere for maximum leak protection is utilized in the Mark 1. The Mark 3 uses the same magnetic drive of the Mark 1, but it can be used for multi-turn applications with 1 to 25 revolutions, such as gate valves. A through shaft drive is incorporated in the Mark 4 making the unit a lower cost alternative to the Mark 1 for applications that are not as demanding. Also featured in the Mark 6 is a patented magnetic design that completely seals the switch cavity. The Mark 6 offers hermetically sealed reed switches that are perfect for high cycle rate applications and low current uses such as computer and PLC control systems.  Dimensional Information

General
Enclosure Rating: Weatherproof and explosion-proof. NEMA 1, 2, 3, 3R, 3S, 4, 4X, 6, 7, 9, 12, 13. UL rated: Class I, Div. 1 & 2, Groups B, C, D; Class II, Div. 1 & 2, Groups E, F, and G. CSA rated: Class I, Div. 1 & 2, Groups A, B, C, D; Class II, Div. 1 & 2, Groups E, F, and G; Submersible to 50 feet. SAA rated: Certified Ex d IIC T6 IP68 15 meters). ATEX pending. Housing styles M and N are NEMA 4, 4X only.
Electrical Connections: Screw terminal. Optional factory sealed leads that are 36" (914.4 mm) of 18 AWG.
Conduit Connection: 3/4" female NPT standard. Optional one or two 1/2" female NPT.
Mounting Orientation: Not position sensitive.
Weight: 4 to 6 lb (1.5 to 3.0 kg).
Operational Life: Over 10,000,000 cycles.
Agency Approvals: UL and CSA. SSA optional. ATEX pending.
Patents: US 4214133, 4647733, 4831350, 5357067, and other patents pending.

Mark 1, 3, 4 and 6 with Switch Outputs
Temperature Limits: -65 to 180°F (-54 to 82°C). Switch Type C rated to 350°F (176°C) for 600 hours, Switch Type T rated to 250°F (121°C) continuous.
Switch Type: See Complete Model Chart on "Ordering" Page.
Electrical Rating: See Complete Model Chart on "Ordering" Page.
Set Point Adjustment: Mark 1 and 4: 5 to 360°; Mark 3: 1 to 25 revolutions; Mark 6: 45 to 180°.

Mark 1, 3 and 4 with Potentiometer
Accuracy: ±0.5% of full span. Optional ±0.25% of full span.
Temperature Limits: -40 to 180°F (-40 to 82°C).
Power Rating: 1.5 watt maximum.
Output Signal: 1000 ohm standard. Optional 2000, 5000, 10000, or 20000 ohms.
Zero and Span Adjustments: Span turn pot with 2000 ohm adjustment. No zero adjustment.
Rotational Travel: Mark 1 and 4: Minimum 0°, Maximum 340°; Mark 3: 0 to 8.5 revolutions.

Mark 1, 3 and 4 with Transmitter
Accuracy: ±0.5% of full span. Optional ±0.25% of full span.
Temperature Limits: -40 to 180°F (-40 to 82°C).
Power Requirements: 5 to 48 VDC.
Current Consumption: 50 mA.
Output Signal: 4 to 20 mA.
Zero and Span Adjustments: Turn pots for adjusting both. Mark 1 and 4: Span is adjustable from 50 to 300°; Mark 3: Span is adjustable from 1.5 to 8.5 revolutions.
Conduit Connection: 3/4" female NPT standard. Optional one or two 1/2" female NPT.
Rotational Travel: Mark 1 and 4: Minimum 0°, Maximum 300°; Mark 3: 0 to 8.5 revolutions.

Mounting kits with drive yoke (see drawing), or slotted lever arm, bracket, fasteners and other zinc plated or stainless steel hardware fit over 2000 popular valves and actuators. A high strength spring tempered Monel drive yoke/coupling is tailored to fit securely to a specific valve or actuator stem. There is no slippage or binding. No special alignment fixtures are required due to switch offset design and yoke to stem engagement that makes installation a "snap". Each kit is specially designed for a particular valve or actuator; making field mounting simple with standard tools.

Mounting kits can be used interchangeably with all models since external mounting features are identical. Rotary valves utilize direct drive couplings and a slotted lever drive is used with linear valves. Lever drives convert linear motion to rotary. Stainless steel visual indicators are standard for direct drive, automated quarter-turn valve applications.