FAQ

Pressure Controllers

What is the media compatibility with Mensor instruments?

Controllers:
Clean, dry gas should be used on all Mensor controllers with the exception of the CPC8000-H, which is hydraulic. Clean Dry Gas should be in accordannce with “ISO8573-1:2010 Class 5.5.4" or better.

ISO8573-1:2010 Class 5.5.4
ISO8573-1:2010 refers to the standard document and its revision, the three digits refer to the purity classifications selected for solid particulate, water and total oil. Selecting a air purity class of 5.5.4 would specify the following air quality when operating at the standard's reference conditions:

  • Class 5 Particulate
    In each cubic meter of compressed air, the particulate count should not exceed 100,000particles in the 1 - 5 micron size range.
  • Class 5 Water
    A pressure dew point (PDP) of 7°C or better is required and no liquid water is allowed.
  • Class 4 Oil
    In each cubic meter of compressed air, not more than 5 mg of oil is allowed. This is a total level for liquid oil, oil aerosol and oil vapor.

Digital Pressure Gauges and Transducers:
Ranges below 15 psi are pneumatic only. Ranges above 15 psi can use fluid. Consult the user's manual for material that will come in contact with the fluid to make sure the fluid is compatible with the material.


What is Intelliscale?

Intelliscale is a way to describe a percent of reading accuracy statement in an easily understood, abbreviated way. An intelliscale sensor can be in a pressure controller, calibrator, digital pressure gauge or a stand alone transducer.

IntelliScale (IS) is a percent (%) of reading (R) specification from the maximum (max) range of the sensor down to a % of the max range and a % of the max range for the balance of the span. For example, if the accuracy of a sensor is designated as 0.01% IS-50, the "0.01%" means that it's accuracy is 0.01% of reading from the max range of the sensor down to 50% of the max range. From 50% of max to the minimum (min) range, the uncertainty is 0.01% of 50% of the max range.

For a bidirectional sensor with a span of -15 psi to 300 psi the max range is 300 and the min range is -15. A 0.01% IS-50 specification for this range provides a 0.01% of R accuracy from 300 to 150. From 150 down to -15 the accuracy is 0.01% of 50% of the max range.

Definitions:
Max = the maximum value of a range, also known as the full scale value. Example, for a range of –15 ... 145, Max = 145
Min = the minimum value of a range. Example, for a range of –15 ...  145, Min  = –15
Full Span (FS) = Max – Min. Example, for 0 ... 145 the Full Span is 145, for –15 ... 145 the Full Span is 160
Reading = The value of the sensor output
IS = IntelliScale is a combination of %Max range and %Reading

What is the meaning of absolute, gauge, barometric, vacuum, bidirectional, ...?

Absolute Pressure
Pressure that is measured relative to (referenced to) absolute zero pressure.

Gauge Pressure
Pressure that is measured relative to (referenced to) atmospheric pressure.

Barometric Pressure
An absolute pressure that measures atmospheric pressure.

Vacuum Pressure
A gauge pressure that is expressed as a positive value below atmospheric pressure. Example: 29 inches of mercury vacuum.

Bidirectional Pressure
A gauge pressure with a span below and above atmospheric pressure.  Example: -15 to +15 psi, -10 to 100 psi etc.

Sealed Gauge Pressure
A pressure that is referenced to a fixed sealed reference, usually standard atmospheric pressure.

Differential Pressure
Pressure that represents the difference between two arbitrary pressures.