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6500 Series Gauge

Senior Fixed Length 4-Bolt Gauges

6500 Fixed Length


The 6500 Series Senior gauges are designed for use in low pressure tanks 0-25 psig [0-1,7Bar] containing diesel fuel, gasoline, fuel oil and lubricating oils.

Used in many applications such as construction equipment, stationary generators, boats, farm equipment and home heating.

General Information & Features

The 6500 Series Senior gauges are available in gear-action models for top, centerline or angle mounting. In lever-action models, centerline is only available.

The standard float is nitrile rubber. Aluminum or stainless steel floats are available at extra cost. The gauge is mounted to a mating Senior flange 2 1⁄2" bolt circle [63,5mm] using four 1⁄4"-28 x 9⁄16" long bolts. The gasket is Buna-N.

Model Number Action Mounting Dial, Sender or Switch Data
6540 Gear Top Senior TwinSite® Sender in choice of 0-30,
0-90, or 240-30 Ohm ranges. #5002S00062
direct-reading dials may also be used
6543 C/L or Angle
L6543 Lever C/L
6550 Gear Top Standard switch #5023S00778 S.P.S.T.,
150 VAC/50 VDC 1⁄2 Amp. Please furnish tank drawings and switch points so proper gauge and calibration can be supplied. Other switches available, see DS-364.
6553 C/L or Angle
L6553 Lever C/L
6560 Gear Top #5025S00570 Senior side-reading fractional
6580 #5002S00062 Senior direct-reading fractional
6583 C/L or Angle
L6583 Lever C/L #5002S00547 Senior direct-reading fractional


Data Sheet

MS-501/502 Installation Instructions

Adapters 22 Series - Senior Sheet Steel

Adapters 22 Series - Senior Machined Steel

Adapters 22 Series - Senior Zinc

General Specifications*


Accuracy depends upon proper gauge sizing. Senior dials ±6%, TwinSite® dials ±10%. Accuracy may be less depending upon tank shape. Accuracy may be less near full and empty. Accuracy may be less if tank is not level. This gauge is not to be used for filling. All accuracy estimates are expressed as a percent of full scale.


-40°F to 158°F, -40°C to 70°C.


Point exposed portions of gauge, less dial, for marine applications.

Shock & Vibration

Suitable to mobile applications.


0.5 watts maximum for TwinSite® versions.

Tank Pressure

Up to 25 PSIG [1,7 Bar].


These direct indicating gauges are UL listed for flammable liquids. Some modesl UL recognized for marine service.


Note: For installation instructions see MS-501/502 (mounting standard).


When Ordering Specify:

1. Gauge model number.

2. Tank diameter and riser height.

3. Mounting location.

4. Ohm range on TwinSite® versions.

5. Preferred switch on switch gauges, if other than standard.

6. Any listed options or preferences.

Materials of Construction*


Die cast aluminum.

Centershaft, Support Tube & Float Rod

Tempered aluminum.

Gears, Cross Stud & Bearing

Stainless steel.

Drive Magnet


Gear Housing

Acetal plastic or aluminum.


Nitrile rubber.


Buna-N, 0015-00004 or 0015-00079.

Direct Reading Dial

Aluminum with acrylic crystal, hermetically sealed.

Side Reading Dial

Aluminum with polycarbonate crystal, hermetically sealed.

TwinSite® Sender


Mounting Bolts

Zinc-plated steel 1/4"-28 x 9/16" long.


*Materials and specifications are subject to change without notice. Pressure ratings subject to change due to temperature and other environmental considerations.