Model 120 Series Filter Minder
Piston-Type Differential Pressure Gauge MEDIUM RANGE: 0-5 P.S.I.D. to 0-110 P.S.I.D. (0.35 to 7.0 bar)
A low cost differential pressure gauge for use in measuring the pressure drop across filters, strainers, separators, valves, pumps, chillers, etc., and for local flow indication and control.
Simple, rugged, compact design.
Working pressure 6000 P.S.I.G. (400 bar) models 120-A and 120-S.
Working pressure 5000 P.S.I.G. (340 bar) models 120-M and 120-N.
Over-range protection to max. pressure.
Aluminum or 316 stainless steel housing with 316 stainless steel internals.
Monel or Aluminum Bronze housing with monel internals.
Weather-resistant construction standard.
Accuracy +3-2-3% full scale (ascending).
Shatter resistant lens.
More cost effective and more accurate than using two pressure gauges in monitoring differential pressure.
2-1/2" and 4-1/2" plastic dial assemblies.
3-1/2" and 4-1/2" annodized aluminum dial assemblies.
Uni-directional or bi-directional.
Five Year Limited Warranty
Differential pressure is sensed by the movement of a floating piston magnet against a calibrated spring. The gauge pointer, outside the pressure housing,follows the movement of the piston magnet and indicates differential pressure.
Available with magnetically actuated hermetically sealed CSA listed reed switches to provide high and low limit alarm or control.
An optional maximum indication follower pointer provides automatic indication of maximum differential occuring during a time period or system cycle.
Reversed pressure ports are optionally available to facilitate installation and readability depending on which side of a filter, etc., the instrument must be installed.
Why use a dp gauge like this, instead of one or two pressure gauges to monitor a filter? Let's take a typical filter application ?1000 P.S.I.G. system pressure and 25 P.S.I.G. maximum dp. Two 1% accuracy pressure gauges (0-2000 P.S.I.G.) could have a combined error of +40 P.S.I.G. (more than the maximum allowable dp!) A 0-50 P.S.I.D. Model 120 would have an error of +1 P.S.I. at a reading of 25 P.S.I.D., 40 times the accuracy of more costly pressure gauges!
NOTE: Due to precision sizing of piston and body bore, leakage across the piston will not exceed 15 SCFH air at 100 P.S.I.D. at ambient conditions.
The Model 120 Filter Minder gauge is available with one or two hermetically sealed reed switches.The switches are adjustable (see table for adjustment range) within a defined percentage of the full scale range of the gauge and are available in SPDT and SPST, normally open or normally closed configurations for various load power ratings.
The switches can be set to activate or deactivate on rising or falling pressure.All hazardous location switches are CSA & UL Listed.The CSA & UL listings are for the entire design and not just the enclosure.All standard and weatherproof units are CE marked for conformance with the Low Voltage Directive to harmonized standard EN 61010-1.
The standard reed switch is enclosed in a weather-resistant plastic housing. Adjustment of the switch setting is made with an external screw adjustment.The switch functionality will be different for gauges with bi-directional operation for positive and negative delta pressure. For example a SPDT switch with positive applied to the gauge, the red wire will be N.O. and the black will be N.C.. For negative the functionality will be reversed.
Location for a single SPDT (grommet or conduit) switch will be on the bottom of the gauge body for a normal port and on the top for a reverse port. Locations for a single SPST (grommet or conduit) N.O. or SPST N.C. switch will be on the bottom and top respectively for a normal port gauge.
The locations will be reversed for a reverse port gauge. For more details request IM 120/latest.
A non-indicating (no dial) differential pressure switch is also available.
