WORLD METEOROLOGICAL ORGANIZATION

SPECIFICATIONS OF EQUIPMENT FOR MODERNIZING THE REGIONAL INSTRUMENT CALIBRATION CENTRE

AT THE KENYA METEORLOGICAL DEPARTMENT (KMD), NAIROBI, KENYA

NOVEMBER 2008

1. CALIBRATION CHAMBER FOR HUMIDITY AND TEMPERATURE CALIBRATION IN AIR AND THE REFERENCES

Technical Specifications:

Control Range for Temperature and Humidity

Minimum usable Temperature control range-10…+60°C or more

Display Requirements…Able to display both Humidity and temperature both the set point and current values.

Communication InterfacesSerial RS232, USB digital output in both temperature and resistance

Meassured range …Variable measurement current. Spanning at least the range 0.1 Ma to 0.5mA.

Measurement method….dew point mirror or Aspirated psychrometer pair.

Settling Time…..Less than 30 minutes after change in Atmospheric parameter.

Measurement Model….Uses the ITS90 Reference fungtions and deviation equations with internally stored coefficients with ability to automatically switch coefficients as the temperature changes ranges

Resolution …..10 Mk and OR 1 x 0.003 ohms

RTD Compatibility….Suitable for both 25 Ohms and 100 ohms four wire resistance temperature sensors.External Reference…..Capacity to attach at least one external reference hygrometer such as a dew point mirror

Humidity control range as wide as possible. Typical control range (10%-95%)Warranty period……..At least 12 monthsService Life………….10yrs

Measurement Uncertainty

Total reference value measurement uncertainty Total measurement uncertainty atleast0.025 deg. Centigrade for Temperature and 0.3 deg centigrade for dew point / ± 2% RH

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Chamber Volume:

About 300…500 litres to allow calibration of several thermographs/hygrographs at the same time

Electricity Supply:

Preferably 3 phase: 415V AC /50HzAnd 240v/50 Hz single phase

Reference Measurement Instruments

Accurate reference measurement instruments for both variables should preferably be delivered with the chamber with detailed technical specifications and calibration certificates

A suitable reference for temperature is a Pt 100 type resistor temperature sensor with ±0.05°C maximum uncertainty. For humidity the reference could be psychrometer or dew point hygrometer

To be able to evaluate the stability and homogeneity of the chamber 4xPt100 type Temperature references of IEC 751 Cass B Calibrated in the Liquid bath should be supplied

Warranty period….At least 12 months

Service Life…….10 years.

2. STIRRED LIQUID OIL BATH FOR THE CALIBRATION OF THERMOMETERS

AND AWS TEMPERATURE SENSORS

Technical Specifications:

Display Requirements….should display both the set point and current temperature.Communication Interfaces…RS232, USB Able to control temperature and sense bath temperature over the interface.

Resolution…..0.01degrees centigrade both set point and current temperature

Minimum usable control range

Preferably-10…60°C or more

Liquid to be used -ethylene or Specific Silicone oil

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Control stability and uniformity: At least 0.01°C spartial or temporal.

Minimum bath dimension….450mm deep 200mm wide 150mm thick

Top Access dimension…200mmx150mm.

Feature …. Clear panel on the 300 mm x 200mm front face.

Material Compatibility…compatible with bath fluids of silicon oil (Dow coring 50 wt) water, Ethylene Glycol.

Bath calibration volume depth :Preferably about 450mm to allow full immersion of long thermometersThe Liquid bath should have stabilizing block

Electricity Supply240 V AC (British Standard Plug)

Warranty period…12 months

Services Life….10 years.

3. RESISTANCE MEASURING BRIDGE FOR THE CALIBRATION OF AWS TEMPERATURE SENSORS AND REFERENCE

Technical Specification:

Minimum measuring range:60Ω….140Ώ Maximum uncertainty±0.005Ώ serial or USB port10-15 measuring channels or a separate selector switch for 10-15 sensorsThe resistance measuring bridge should have internal standard resistor to avoid Temperature Stabilization if External standard resistor is used

Electricity Supply:240 VAC (British standard plug) /50HZ

Temperature ReferenceA pt 100 type resistor temperature reference, calibrated and certified usable for calibration in liquid

Maximum uncertainty±0.02Ώ(±0.05°c)

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A water triple point cell might be useful for the periodical checking of the above described reference.

Resolution0.25 Mk and /or 1x 0.0001 Ω

Measurement MethodTrue 4 wire or 6 wire measurement

.Measurement TimeLess than 5 seconds.

Ambient Operating Range18 to 28 degrees Centigrade.

Temperature Coefficient1 ppm/ degrees Centigrade

Measurement ModelUses the ITS90 reference function and deviation equations with internally stored coefficients with ability to automatically swath coefficients as the temperature changes ranges

Warranty periodAt least 12 months parts labour.

Service life 10 years

4. PRIMARY/SECONDARY PRESSURE CALIBRATOR (Pressure Controller, chamber and Reference)

Technical Specifications:

Measurement UnitsAbsolute pressure in hPa

Minimum usable control range:500…1100 hPa; extended lower limit down to 500hPa favourable

Control Stability:At least ±5Pa (to create a reliable calibration environment at 10Pa level)

Control Volume: Must operate well for small control volumes like 10…50cm³, but a capability to control larger volumes like 50… 100 litres is considered as and advantage.

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Must be delivered with suitable pumps with Appropriate air filtering facility. Communication interfaces…. RS232,USB or IEEE488 able to control and sense current pressure over the interface

Chamber dimension: Test chamber to be able to test several Aneroid barometers and ,barographs Should have hooded facility for calibrating mercury Barometers such as Q-PARTEN BAROMETER.Resolution..0.001 hPa

Ambient operating Range…18 deg Cent. To 28 deg Centigrade.

Max pressure Sensor Drift….0.1 hPa/ Year.

Electricity Supply: 240V AC (British standard plug) /50 Hz

Pressure Reference

Standard (digital barometer with display), range and uncertainty of 0.05 hPa at 95% confidence interval, to fit with the controller. Both reference and controller should be calibrated and certified.

Warranty Period… At least 12 months parts Labour.

Service Life… 10 yrs

5. TWO REFERENCE PYRONOMETERS FOR THE CALIBRATION OF GLOBAL RADIATION SENSORS AND A DATA LOGGER

Technical Specifications for Pyranometers:

Secondary standard grade (or first class radiometer in WMO terms (3)) .Good long term stability of ±0.5 to 0.8% for high quality essential.Calibration certificate must be included.

Technical Specifications for Data Logger:

Data logger should be flexible in measuring many sensors (optimum 5 to 10 units)Simultaneously, possibly with large differences (many sensor types)

Measurement range:0…25 mV

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Resolution: Min. 2μV

Differential Inputs:

Input Impedance:At least 2MΏ . Measurement interval : 1/s for all channels

Suitable for outdoor use close to the sensors being measured

Serial or USB port (output)

Logger power supply for 240 VAC (British standard plug) /50 Hz.

Warranty Period……At least 12 monthsService Life………..10 yrs.

6. LABORATORY POWER SUPPLY (To be used as a sensor power supply in calibrations)

Specifications:

Output voltage range:3…24VDC

Voltage readout resolution: 0.1V

Output current:

Max 1 A; adjustable current limiting“Laboratory grade” voltage regulation against changes in loading, input voltage and temperature variation. AC power network noise suppression.

AC input240V AC (British standard plug) / 50Hz

7. Tester for mechanical clockworks

Tester is needed for the checking and calibration of the clockworks used in graphs.

Technical specifications:

Suitable for mechanical clockworks

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Maximum deviation:1 s/24 h

8. WATER PURIFIER TO PRODUCE LABORATORY GRADE WATER

Laboratory grade water is needed for some calibrations and instruments, for example humidity calibration chamber, psychrometer and precipitation calibration.

Technical Specification:Purity of produced water:Laboratory grade

Method of Purification:Preferably reverse osmosis

Production Capability:At least 10 1/ dayWarranty Period……….12 monthsService Life………..10yrs

9. WIND TUNNEL

Designed as test equipment for calibration of wind sensors.

Should allow wide rotation operation range and stable rotation speed.

Should include different reference equipments (like differential pressure gauges, thermo anemometers and laser Doppler Anemometers and associated accessories like test adopters, PC’s ,printers, monitors etc.)

There should also be customer made software solutions for semi or fully automatic operation including print out of final reports.

Specifications:

Measuring range:0.15 to 50 m/s

Degree of turbulence ……………………..At V= 3m/s: ±0.4%measured in tunnel ……………………… At V=10m/s: ±0.4% cross section with resolutions at 0.5Hz:……. At V= 40m/s: ±0.3% Drive power .------------------- approximately 40kw

Drive control: …………………. Silicon Controlled Rectifier (SCR)

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Power supply:……………………0/400 VAC, 50Hz /3ph

Motor: ………………………. SCR controlled DC motor

Should also be Included is a control cabinet.

The above specs for wind Tunnel are for minimum and do not limit us to particular model or product.

Warranty Period………12 monthsService Life……………..10 yrs

10. AWS HUMIDITY SENSORS SALT CALIBRATOR.

For the checking and adjusting of the AWS humidity sensors a universal salt calibrator (saturated salt solution method) is favourable.

Specifications:

Two salt chambers (for low and high adjusting points)At least two salt solutions needed.Good stability of the chamber temperatureChamber temperature measurable with the uncertainty.

11. PRECIPITATION SENSORS CALIBRATOR.

A calibrator which can calibrate several sensors. The accuracy requirement is 0.1mm of precipitation.

ADDITIONAL REQUREMENTS BELOW TO BE COSTED BY THE BIDDER.

12. Factory and on Site TrainingFactory training of three maintenance personnel for two weeks and On Site training of all staff for one week. RIC… Factory Maintenance and Operational Training will be to familiarize the maintenance personnel with diagnostic troubleshooting and operational principles of the RIC SYSTEMS.The personnel will be entitled to Airfare, Hotel accommodation, Daily subsistence allowance and local Transportation.

13. Factory Acceptance Tests (FAT).

Shall be carried out by the manufacturer in their premises. Two Department representatives will participate in preparation of; Factory acceptance Test Procedures in advance, Witnessing FAT Procedures, and a FAT Report. The cost will include,

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cost of printed FAT material, Air Fare, Hotel accommodation and Daily Subsistence Allowance and Local transportation for the two participants.The factory acceptance report will be included in acceptance test Document.

14. Site Acceptance Test (SAT)

Will be carried out at the end of installation and site training.The Site acceptance test will be included in in the acceptance test Document.

15. Recommended Spare parts

Minimum set of spares should be available on delivery of the instruments.The bidder to guarantee availability of spares even after expiry of warranty date.

16. Installation costs

Installation, Supervision will be done by the Supplier systems Engineer, assisted by Kenya Meteorological technical personnel during the installation. Other costs include cost for Hotel accommodation, Travel, cable work, earthing, and civil works.

17. After sales support

To maintain standards and their calibration in the period of ten years after installation.

18. Calibration certificate-The certificate should have traceability to SI standards.

19. Manuals-Technical and Operational manuals for each equipment delivered in English

Evaluation criteria

20. Proposals will be evaluated on the basis of their compliance/non-compliance to the requirements detailed in the technical specifications of each of the equipment listed above.

21. Other considerations will include the provision of the following:

(a) Factory and on Site Training(b) Factory acceptance tests(c) Site acceptance tests(d) Recommended spare parts(e) After sales support(f) Calibration certificates, and (g) Technical and operational manuals in English

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