Amendment_3_260902-SubmersibleLevelTransmitter-20110512.doc

USDA Forest Service Project Specifications

SECTION 260902

submersible level (pressure) transducer INFO Subject \* MERGEFORMAT

SUBJECT \* MERGEFORMAT

1. Part 1 - General

1.01 description

A. This submersible pressure transducer shall be suitable for continuous submergence in either water or domestic sewage. The connection Junction box may have up to 100% RH condensing atmosphere.

1.02 Submittals

A. Submit shop drawings and equipment catalog data and manufacturer's installation operating and maintenance instructions for approval of the following items in accordance with Section 260010.

B. Provide both hard copy and manufacturers original PDF files with submittals in electronic form.

1.03 References

A. 260010 - General Technical Provisions.

B. 260050 - Basic Methods and Materials

2. PART 2 - PRODUCTS

2.01 submersible Pressure Transducer Specification

A. Range:

0 – 10 PSIG = 23.1 feet of water.

B. Overload:

Proof Pressure: 2 times FS

C. Burst Pressure:

35 times FS

D. Materials Contacting Media:

Transducer: 17 – 4 Stainless Steel

E. Cable:

FDA Approved Material in contact with water

F. Weight with 32’ Cable:

20 oz.

G. Electrical:

Input: 7 – 35 VDC

H. Output:

4 – 20 mA

I. Supply Sensitivity:

0.01%FS/Volt

J. Max. Loop Resistance:

(Vs-7) x 50 Ohms

K. Insulation Resistance:

> 1000 M Ohms at 50 VDC

L. Approvals:

CE and UL

M. Intrinsic safety:

For sewage applications, sensor shall be ETL approved Intrinsically Safe for Class 1, Groups C and D

1. Intrinsically safe transducer shall be suitable for use in conjunction with Gems Barrier P/N 195318.

2. Entity parameters are: Voc=28VDC, Isc=89mA, Ca=1.1microfarads, La=35.7microHenrys

N. Performance:

1. Accuracy: 0.15% (Includes hysteresis, non-linearity and repeatability)

2. Long Term Drift: 0.2% FS/year (non-cumulative)

3. Zero Tolerance: 0.1% of span

4. Span Tolerance: 0.1% of span

5. There shall be no allowance in design for zero and span adjustments

6. Strain gages in sensor should be produced by CVD process

7. Thermal Error: 1% FS Typical with “B” accuracy option

8. Compensated Temp: -5F to 180F

9. Operating Temp: -5F to 125F with Immersible Cable

10. Pressure Port: G1/8 female (others available)

11. Vibration: 35g peak, 5 to 2000 Hz

12. Acceleration: 100g in any direction. 0.032%FS/g for 15 psi decreasing logarithmically to 0.0007% FS/g for 6000 psi

13. Shock: Withstands free fall to IEC 68-2-32 procedure 1

14. Transducers should meet the requirements for CE marking as detailed in EN50082-2 for susceptibility. Test methods are defined in the following test procedures:

EN61000-4-2 Electrostatic Discharge

+/- 4kV contact discharge

+/- 8kV air discharge

EN61000-4-4 Fast Burst Transients

+/- 2kV 2 minutes

O. Accessories:

1. Potable water and Intrinsically Safe designs shall be compatible for use with Gems transient protector, P/N 195319.

2. Provide Moisture protection of vent tube for potable water or Intrinsically Safe transducer shall be accomplished using a desiccant dryer tube, Gems P/N 195316. Provide one spare desiccant dryer tube for each transducer.

P. For Potable Water:

1. Provide Gems Sensors Inc. Model 2600BGF1509M3GBxxx transducer with 32 feet of cable. Analog pressure level transducer with special 0 – 10 PSIG range and FDA approved material covering 38 feet of the cable. Verify cable lenth required prior to order with actual distance to tank.

Q. Manufacturer

1. Transducer and accessories supplied by Gems Sensors Inc., 1 Cowles Road, Plainville, CT 06062

2. Rep Ewing Foley

3. PART 3 - EXECUTION

3.01 installation & testing

A. Install sensor in water tank or sewage tank as shown on drawings. Tighten compression cord grip carefully to avoid damage to sensor cable.

B. Minimum bending radius of cable: 6”

C. Install vent tube to moisture trap with tube end down to keep free moisture from entering vent tube.

D. Install vent tube moisture trap, transient voltage surge suppressor, control cable lightning arrestors as shown on drawings.

E. Provide nameplates for all equipment in sensor connection J box as per 16010.

F. Test sensor by putting plastic electrical tape at one-foot intervals from the bottom of the sensor and immersing the sensor in water at one foot intervals and recording the current (4-20MA) up to the maximum depth of the liquid in the tank installed. Verify that resultant current meets accuracy specification above. Replace any unit not meeting specification; re-test until accuracy specification is met. Utilize a 4-1/2 digit Fluke multi-meter or equal for testing. See 16010 for complete testing requirements.

END OF SPECIFICATIONS

Pressure transducer, 32’ Cord with breather tube, 4-20MA 2 Wire submersible pressure transmitter 0-10psi = 23.1’ head water UL & CE recognized

1/8” NPT Fitting

Desiccant dryer tube

Dessicant tube, lightning protectors TVSS unit mounted in Nema 43X J box at water tank

End of Section

05/12/2011 Project Name 26902 - 2/4 Submersible Level Transducer