Question 1

What is an axial gradient?

Accepted Answer

Temperature difference/temperature gradient from the bottom – maximum immersion depth – to the top - surface of the calibrator.

Question 2

What does radial gradient mean?

Accepted Answer

Temperature difference between the individual bores of an insert.

Question 3

What does stability mean?

Accepted Answer

The temperature difference between the minimum and the maximum for fluctuating temperature, taken over 30 minutes.

Question 4

What is the difference between a dry well calibrator and a micro calibration bath?

Accepted Answer

Dry well calibrators/micro calibration baths consist of a thermally insulated metal block which is heated, and for instruments which work with Peltier elements, which can also be cooled. The reference, which the calibrator controls, is mounted directly into the metal block. The working range of commercially available temperature calibrators, using Pt resistance thermometers as a standard, extends from approximately -45 °C to 650 °C. Calibrators that work with Peltier elements are typically used from -35 °C to 165 °C, and those that are fitted with resistance heating from 35 °C to 700 °C. In addition, there are high-temperature dry well calibrators which can be used, depending on the model, up to 1300 °C. They work with precious-metal thermocouples as standards and control thermometers. In these cases, the measurement uncertainties are higher than in calibrators which use a resistance thermometer as a standard. The working range of micro calibration baths is (unlike the dry block calibrators) strictly limited, due to the use of liquids (usually silicone oil) instead of inserts. In order to be able to calibrate using these liquids, they must be sufficiently viscous at ambient temperature. This requirement then limits the upper end of the temperature range to approximately 250°C. They do have the advantage of homogeneous mixing of the liquid due to a magnetic stirrer at the bottom, meaning no axial nor radial gradients are observed.

Question 5

What is the minimum immersion depth with dry well calibrators?

Accepted Answer

The minimum immersion depth for dry well calibrators is 70mm. This is driven by the axial gradient, since warm air rises from the bottom up. Should this minimum immersion depth of 70mm not be reached, an external reference thermometer must be used for calibration. This is then placed on the same level as the object to be calibrated and the results are compared with each other. The other alternative is to use a micro calibration bath, since with the thorough mixing of the liquid, there is no requirement for a minimum immersion depth. Rule of thumb for recommended immersion depth: 1. Diameter of the test item x 15 or 2. for a known sensitive length: sensitive length + Diameter of the test item x 10

Question 6

What material are the inserts for a dry well calibrator made from?

Accepted Answer

The material for the inserts depends on the temperature range of the dry well calibrator. The selected material should have a temperature range far remove from the melting point. e.g. for a temperature range of -35…165°C Material = aluminium 40…650°C Material = brass 200…1100°C Material = Inconel

Question 7

How must the inserts be designed in order to get the best results?

Accepted Answer

The inserts should be drilled in accordance with the diameter of the test items. In general, the bore diameter, taking the thermal expansion of the test item into account, should be selected to be as small as possible. Air gap between the thermometer and the bore will act as resistances to heat transfer and will significantly affect the heat transfer through heat conduction. As a consequence, the test bore diameter should be a maximum of 0.5mm larger than  the external diameter of the thermometer.

Question 8

When is a shut-off valve needed on the CPP1000 - M/L hydraulic test pumps?

Accepted Answer

When test units with a large internal volumes should be calibrated with it (e.g. pressure gauge from NS 100). For pressure transmitters with a small channel bore volume, a shut-off valve is needed. The volume change of the piston with a complete spindle hub is only 3.9 ccm In addition, a check valve is necessary when reference devices are used with large internal volumes (e.g. NS100 pressure gauge). When using the CPH series reference pressure transmitters and pressure transmitters on the test item side, a shut-off valve is required.

Question 9

Why is no certificate issued for the CTB9400, CTB9500?

Accepted Answer

Calibration baths of such a volume always require the use of an external reference. The display is no longer reliable, owing to the volume and the gradient. For these reasons, no certificate will be issued for these baths.

Question 10

How to find the ASL products under WIKA?

Accepted Answer

New product designations for the ASLproduct portfolio: The company ASL, a leading manufacturer of AC resistance bridges and high-accuracy hand-held thermometers, has been part of the WIKA Group since January 2013. With this acquisition the product range in the field of calibration technology with the measurement parameter temperature offered by WIKA has been extended. In order to integrate the products into the WIKA websites, the previous model designations have been changed. Regarding their technical features the products remain unchanged. Old name New name Data sheet Primary standard F900 CTR9000 (preciseness 20 ppb) CT 60.80 AC resistance bridge F18 CTR9000 (preciseness 0,1 ppm) CT 60.80 AC secondary resistance bridge F700 CTR9000 CT 60.80 Precision AC resistance bridge F650 CTR6500 CT 60.40 Resistance bridge F600 CTR6000 CT 60.30 Precision thermometer F500 CTR5000 (Phase-Out) CTR3000 CT 60.20 CT 60.15 F252 CTR5000 (Phase-Out) CTR3000 CT 60.20 CT 60.15 Precision thermometer F200 CTR2000 CT 60.10 Hand-held thermometer F100 CTH7000 CT 55.50 Multiplexer SB148 CTS9000 CT 60.80 SB158 CTS9000 CT 60.80 SB500 CTS5000 CT 60.20 Resistance thermometer T100 ..., 5187SA CTP5000 CT 61.20 AC/DC standard resistors RR, RW CER6000 CT 70.30

Question 11

What do different abbreviations like RTD, PRT, SPRT… mean?

Accepted Answer

RTD (Resistance Temperature Detector) – a temperature sensor whose resistance changes with temperature PRT (Platinum Resistance Thermometer) – RTD using platinum wire for the resistance element Pt1000 – PRT with 1,000 Ohm at 0 °C. Pt500 – PRT with 500 Ohm at 0 °C. Pt100 – PRT with 100 Ohm at 0 °C. Pt25 – PRT with 25 Ohm at 0 °C. Pt10 – PRT with 10 Ohm at 0 °C. SPRT (Standard PRT) - high-stability PRT designed for use as a reference thermometer

Question 12

What is a SMART probe?

Accepted Answer

The "SMART probe" is a precision RTD sensor with an electronic memory in its coupler connector. This memory chip stores the coefficients of the calibrated sensor and a complete history of the probe. This history includes the maximum and minimum value that the sensor has been exposed to and also the calibration dates.

Question 13

What is the Kn factor?

Accepted Answer

All piston-cylinder units and masses which can be mounted on Desgranges & Huot pressure balances are built around a nominal mass-to-pressure conversion coefficient, Kn. The nominal effective area of each piston-cylinder size is such that, under standard conditions, a piston loaded with 1 kg of mass will generate a pressure equivalent to the Kn value. All mass values, including the mass of the piston and of themass loading bell are adjusted to be a whole number or a fraction of a kilogram. The nominal pressure defined for a pressure balance is calculated as Kn multiplied by the mass loaded in kg. Corrections are applied to Kn to calculate the pressure defined within the accuracy tolerance of the piston-cylinder assembly used. The use of Kn and whole-number masses in no way affects the traditional pressure equation nor the factors that affect a pressure measurement made with a pressure balance. Kn is the basis of a coherent relationship between mass, effective area and pressure throughout the Desgranges & Huot pressure balance series. It is intended to be a tool that reduces operator confusion and errors by simplifying the calculation of mass loads and measured pressures.

Question 14

Who is Mensor and what do they do?

Accepted Answer

Mensor was founded in 1969 in Houston, Texas, and has been dedicated to the design and manufacture of the finest high-accuracy measurement, calibration and control instruments and test systems for pressure available. In 1978, Mensor relocated to San Marcos, Texas. From the first Mensor quartz manometer produced for the aviation industry in 1970 to the advanced computer-controlled pressure calibration systems of today, Mensor's name has become synonymous with reliability and innovation in the field of precision pressure measurement, control and calibration.

Question 15

How do I zero a sensor?

Accepted Answer

Gauge : Vent the transducer that you are zeroing. Perform a single point "Zero" calibration for that sensor by following the instructions for the specified product. Absolute : Zeroing an absolute sensor requires a vacuum standard such as a Hastings gauge or Baratron. To properly set zero on an absolute sensor a vacuum must be pulled down to a pressure close to 600 mtorr. When the vacuum pressure has stabilized perform a single point "Zero" calibration for that sensor by following the instructions for the specified product.

Question 16

What is the media compatibility with Mensor instruments?

Accepted Answer

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.

Question 17

What are the calibration capabilities of the Mensor calibration lab?

Accepted Answer

Calibration capability chart summary 17025 Calibrations Calibration Type Range Lowest Full-Scale Range Pneumatic Gauge Pressure -ATM to 6000 psig 0...10 inH20 (~ 25mbar, 2.5kPa) Pneumatic Absolute Pressure 0 to 6015 psia 0...7.5 psia (517 mbar, 51.7 kPa) Hydraulic Gauge Pressure 0 to 30,000 psig Hydraulic Absolute Pressure 0 to 30,000 psia

Question 18

What is Intelliscale?

Accepted Answer

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

Question 19

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

Accepted Answer

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.

Question 20

What is Air Data with respect to the avionics industry?

Accepted Answer

Air data is a measurement of the physical characteristics of the air mass that surrounds an aircraft. Temperature and pressure are the two maim parameters. Using these, flight parameters can be calculates, including air speed, altitude, rate of climb, angle-of-attack and angle-of-side-slip.

Question 21

What is a Custom System?

Accepted Answer

A custom System is a rack mounted, cart mounted, bench mounted, or any other conceivable configuration of components, that is designed by the customer or designed in collaboration with the Mensor Custom Solutions department, to satisfy a specific need that can only be met by incorporating multiple integrated components. Systems may consist of (but are not limited to): pressure controllers, digital volt meters, manifolds, power supplies, pressure volumes, power distribute components, point of use pressure and temperature transmitters and computers. in addition custom or standardized software can be incorporated to communicate system parameters, collect data, print reports and control the integration of components.

Question 22

What is an AC resistance thermometry bridge?

Accepted Answer

AC Resistance thermometry bridge technology is explained in detail in the Calibration Technology brochure entitled " Advantages of AC resistance thermometry bridges ".

Question 23

How do I start the process of designing a Mensor Custom System?

Accepted Answer

The first step is to contact your local sales representative or call Mensor directly at 512-396-4200. A sales person can determine if a standard product will meet your needs or if a custom system is required. If a custom system is required the sales person will initiate contact between you and the Mensor Custom Solutions department. An Engineer in the Custom Solutions department will consult with you and design or assist in the design of a system that will meet your specific needs.

Question 24

What is a coalescing filter?

Accepted Answer

A Coalescing Filter separates two ‘phases’, for example the removal of water aerosols and droplets from a gas. Coalescing filter housings have three ports, the inlet (wet gas with aerosols and droplets), the outlet (gas) and the drain (liquid). Coalescing filter elements installed in a housing separate the liquid from the gas. The liquid drains to the bottom of the housing and can be manually or automatically eliminated from the housing via the drain connection and valve. A gas free of aerosol and droplets exits the outlet port. Coalescing filters also will remove solid particles but are specifically designed for removing liquids, regular particle filters will not behave the same way.

Question 25

What is a liquid separator?

Accepted Answer

A liquid separator uses gravity and a pressure vessel to separate gas from liquid contamination. Gas contaminated with liquid passes into the volume through a tube. liquid contamination drops to the bottom of the volume and gas travels out through an outlet located at the top of the volume. The volume must be drained occasionally to prevent the liquid from reaching the outlet.

Question 26

What is an air data test set?

Accepted Answer

An air data test set is a an electronic controller which, based on a supply pressure, automatically provides a pressure at a variable and adjustable rate. Air data test sets are specifically developed to convert the pressure to be controlled into a height or rate of climb and velocity. As a result of the high accuracy, control stability and ability to simulate altitude and velocity, an air data test set is particularly suitable as a reference for aircraft workshops and also for instrument manufacturers and calibration laboratories in the aviation industry, in order to make calibrations on sensors and displays.

Question 27

What is A2LA?

Accepted Answer

The American Association for Laboratory Accreditation (A2LA) is a nonprofit, non-governmental, public service, membership society. they are the only independent (meaning that they are not governed by another, "parent" organization), non-profit, internationally-recognized accreditation body in the United States that offers a full range of comprehensive laboratory and laboratory-related accreditation services and training. Services are available to any type of organization, be it private or government. All of our accreditation programs are based on internationally-accepted criteria for competence. In addition to the accreditation of laboratories, A2LA offers programs for the accreditation of inspection bodies, proficiency testing providers, reference material producers and product certification bodies.

Question 28

What product brands does the Mensor facility in San Marcos, Texas repair?

Accepted Answer

Mensor, DH-Budenberg, DHI (Desgranges & Huot), WIKA and ASL branded products.

Question 29

What is 17025?

Accepted Answer

17025, or more specifically, ISO/IEC 17025:2005 is (quoting from the standard's scope) an international standard that "specifies the general requirements for the competence to carry out tests and/or calibrations, including sampling. It covers testing and calibration performed using standard methods, non-standard methods and laboratory-developed methods." The calibration laboratory at Mensor is accredited to ISO/IEC 17025:2005 by A2LA.

Question 30

Is Mensor's laboratory accreditation available on this website?

Accepted Answer

Yes, the accreditation is available at this link, or can be viewed in the Customer Service section of this website

Question 31

What is ILAC?

Accepted Answer

From the ILAC website: "ILAC is the International Laboratory Accreditation Cooperation for both laboratory and inspection accreditation bodies formed more than 30 years ago to help remove technical barriers to trade. Accreditation is the independent evaluation of conformity assessment bodies against recognised standards to carry out specific activities to ensure their impartiality and competence. Through the application of national and international standards, government, procurers and consumers can have confidence in the calibration and test results, inspection reports and certifications provided...." Mensor is accredited by an ILAC signatory: A2LA.

Question 32

What is calibration traceability?

Accepted Answer

Calibrations performed at Mensor are traceable to the International System of Units (French: Système International d'Unités), SI units. For the Mensor Laboratory, the hierarchy of traceability to this standard system of units is illustrated below, starting at the SI units established by CGPM and progressing to Mensor. 1.SI (international system of Units) - CGPM (General Conference on Weights and Measures) 2.CIPM (International Committee for Weights and Measures) 3.BIPM / ILAC (International Bureau of Weights and Measures / International Laboratory Accreditation Cooperation) 4.NIST (National Institute of Standards and Technology) 5.A2LA accredited labooratoories (American Association for Laboratory Accreditation) 6.Mensor Other divisions of WIKA may have different traceability paths.

Question 33

What is the warranty on Mensor repairs?

Accepted Answer

All repair work is covered by a ninety (90) day warranty, which includes parts and labor. Please notify Mensor immediately if you experience a problem or if the instrument is not performing to your expectations.

Question 34

Where are the global repair facilities for Mensor products?

Accepted Answer

All Mensor pensor products can be repaired at the Mensor facility in San Marcos Texas. Global repair facilities are listed in the international calibration service page.

Question 35

What is the scope of Mensor's A2LA accreditation?

Accepted Answer

The scope is listed in the 17025 A2LA Accreditation Certificate.

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