Equipment for Regional Instruments Centre at Kenya Meteorological Department
WORLD METEOROLOGICAL ORGANIZATION
SPECIFICATIONS OF EQUIPMENT FOR MODERNIZING THE REGIONAL INSTRUMENT CALIBRATION CENTRE
AT THE KENYA METEORLOGICAL DEPARTMENT (KMD), NAIROBI, KENYA
NOVEMBER 2008
- CALIBRATION CHAMBER FOR HUMIDITY AND TEMPERATURE CALIBRATION IN AIR AND THE REFERENCES
Technical Specifications:
ControlRangefor 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 Interfaces
Serial 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 months
Service 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
Chamber Volume:
About 300…500 litres to allow calibration of several thermographs/hygrographs at the same time
Electricity Supply:
Preferably 3 phase: 415V AC /50Hz
And 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 bepsychrometer 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.
- STIRRED LIQUID OIL BATH FOR THE CALIBRATION OF THERMOMETERS
AND AWSTEMPERATURE 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
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 (Dowcoring 50 wt)water, Ethylene Glycol.
Bath calibration volume depth :
Preferably about 450mm to allow full immersion of long thermometers
The Liquid bath should have stabilizing block
Electricity Supply
240 V AC (British Standard Plug)
Warranty period…12 months
Services Life….10 years.
- RESISTANCEMEASURING BRIDGE FOR THE CALIBRATION OF AWS TEMPERATURE SENSORS AND REFERENCE
Technical Specification:
Minimum measuring range:
60Ω….140Ώ
Maximum uncertainty
±0.005Ώ serial or USB port
10-15 measuring channels or a separate selector switch for 10-15 sensors
The 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 Reference
A pt 100 type resistor temperature reference, calibrated and certified usable for calibration in liquid
Maximum uncertainty±0.02Ώ(±0.05°c)
A water triple point cell might be useful for the periodical checking of the above described reference.
Resolution
0.25 Mk and /or 1x 0.0001 Ω
Measurement Method
True 4 wire or 6 wire measurement
.
Measurement Time
Less than 5 seconds.
Ambient Operating Range
18 to 28 degrees Centigrade.
Temperature Coefficient
1 ppm/ degrees Centigrade
Measurement Model
Uses the ITS90 reference function and deviation equations with internally stored coefficients with ability to automatically swath coefficients as the temperature changes ranges
Warranty period
At least 12 months parts labour.
Service life
10 years
- PRIMARY/SECONDARY PRESSURE CALIBRATOR
(Pressure Controller, chamber and Reference)
Technical Specifications:
Measurement Units
Absolute pressure in hPa
Minimum usable control range:
500…1100hPa; 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… 100litres is considered as and advantage.
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
- 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
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 months
Service Life………..10 yrs.
- 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 input
240V AC (British standard plug) / 50Hz
- Tester for mechanical clockworks
Tester is needed for the checking and calibration of the clockworks used in graphs.
Technical specifications:
Suitable for mechanical clockworks
Maximum deviation:
1 s/24 h
- 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/ day
Warranty Period……….12 months
Service Life………..10yrs
- 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)
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 months
Service Life……………..10 yrs
- 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 temperature
Chamber temperature measurable with the uncertainty.
- PRECIPITATION SENSORS CALIBRATOR.
A calibrator which can calibrate several sensors. Theaccuracy requirement is 0.1mm of precipitation.
ADDITIONAL REQUREMENTS BELOW TO BECOSTED BY THE BIDDER.
- Factory and on Site Training
Factory 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.
- 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, cost of printed FAT material, Air Fare, Hotel accommodation and Daily Subsistence Allowance andLocal transportation for the two participants.
The factory acceptance report will be included in acceptance test Document.
- 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.
- 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
.
- Installation costs
Installation, Supervision will be done bythe Supplier systems Engineer, assistedby Kenya Meteorologicaltechnical personnel during the installation.Other costs include cost for Hotel accommodation, Travel, cable work,earthing, and civil works.
- After sales support
To maintain standards and their calibration in the period of ten years after installation.
- Calibration certificate-
The certificate should have traceability to SI standards
.
- Manuals-Technical and Operational manuals for each equipment delivered in English
Evaluation criteria
- 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.
- 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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