Gefran KN SERIES Data Sheet

NaK FILLED MELT PRESSURE TRANSMITTERS

KN SERIES Voltage output

The KN Series are for use in high temperature applications
where the process temperatures may reach 538°C (1000°F)
such as high temperature engineered polymers.
The K Series utilizes standard melt pressure principles and
construction, but uses a near incompressible (NAK Sodium
Potassium) for pressure transmission.
The K Series strain sensing technology is bonded foil strain
gage.

MAIN FEATURES

• Pressure ranges from:
0-35 to 0-1000 bar / 0-500 to 0-15000 psi

• Accuracy: < ±0.25% FSO (H); < ±0.5% FSO (M)

•Hydraulic transmission system for pressure signal gua-
rantees stability at working temperature (NaK).

Liquid conforming to RoHS Directive.
NaK is defined as a safe substance (GRAS).

•Quantity of NaK contained per model: KN0 series (30mm3)
[0.00183 in3], KN1, KN2, KN3 (40mm3) [0.00244 in3]

•1/2-20UNF, M18x1.5 standard threads; other types avai-
lable on request

• Autozero function on board / external option

• Stem drift Autocompensation function (SP version)

• Inconel 718 diaphragm with GTP+ coating for temperatu­res up to 538°C (1000°F)

• 15-5 PH diaphragm with GTP+ coating for temperatures
up to 400°C (750°F)

• Hastelloy C276 diaphragm for temperatures up to 300°C
(570°F)

• 17-7 PH corrugated diaphragm with GTP+ coating for

ranges below 100 bar-1500 psi up to 400°C (750°F)

• Material of stem 17-4PH

GTP+ (advanced protection)
Coating with high resistance against corrosion, abrasion
and high temperature

AUTOZERO FUNCTION

All signal variations in the absence of pressure can be elimi­nated by using the Autozero function.
This function is activated by closing a magnetic contact loca­ted on the transmitter housing.
he procedure is permitted only with pressure at zero.

AUTOCOMPENSATED INFLUENCE OF MELT
TEMPERATURE

Thanks to internal self-compensation, the KSP series
transmitter cancels the effect of pressure signal variation
caused by variation of Melt temperature.
This reduces at the minimum the read error caused by hea­ting of the filling fluid (typical of all sensors built with “filled”
technology).

The drift values declared in the version with Autocompensation
are valid for media temperatures up to 500°C.

TECHNICAL SPECIFICATIONS

Accuracy (1)

Resolution Infinite

Measurement range

Maximum overpressure
(without degrading performances)

Measurement principle Extensimetric

Power supply

Maximum current absorption 25mA

Insulation resistance (at 50Vdc) >1000 MOhm

Output signal Full Scale (FSO)

Zero balance
(tolerance ± 0.25% FSO)

Zero signals adjustment
(tolerance ± 0.25% FSO)

Span adjustment within ± 5% FSO See Melt manual

Maximum allowed load 1 mA

Response time (10...90% FSO) ~ 1ms

Output noise (RMS 10-400Hz) < 0.025% FSO

Calibration signal 80% FSO

Output short circuit and reverse
polarity protection

Compensated temperature range 0...+85°C

Operating temperature range -30...+105°C

Storage temperature range -40...+125°C

Thermal drift in compesated range:
Zero / Calibration / Sensibility

Diaphragm maximum
temperature

Zero drift (zero)

Zero drift temperature for
Autocompensated version (SP)
within the temperature range
20°C-500°C inclusive the drift
temperature of the housing

Thermocouple (model KN2)

Protection degree
(with 6-pole female connector)

FSO = Full Scale Output
(1) BFSL method (Best Fit Straight Line): includes combined effects of Non­Linearity, Hysteresis and Repeatability.

H <±0.25%FSO (100...1000 bar)

M <±0.5%FSO (35...1000 bar)

0..35 to 0..1000bar

0..500 to 0..15000psi

2 x FSO

1.5 x FSO over 700bar/10000psi

15..30Vdc N, C

10..30Vdc B, M

5Vdc (M) - 10Vdc (N)

5,1Vdc (B) - 10,1Vdc (C)

0Vdc (M, N)

0.1Vdc (B, C)

“Autozero” function

YES

< 0.02% FSO/°C

538°C

1000°F

< 3,5bar/100°C /

< 28 psi/100°F

< 0.005 bar/°C 100 ≤ p < 500 bar

0.0022 %FS/°C p ≥ 500 bar

STD : tipo “J”

(isolated junction)

IP65

MECHANICAL DIMENSIONS

KN0

D1

1/2 - 20UNF

D2

[ ø0.31” -0.002 ]

D3

[ ø0.41” -0.001 ]

D4

D5

A

B

C

KN2

ø7.8 -0.05

ø10.5 -0.025

ø10.67

[ ø0.42” ]

ø12.7

[ ø0.5” ]

5.56 -0.26

[ 0.22” -0.01 ]

11.2

[ 0.44” ]

15.74

[ 0.62” ]

Ch

[Hex]

16

[ 5/8” ]

KN1 KN3

D1

M18x1.5

[ ø0.394” -0.002 ]

[ ø0.63” -0.003 ]

[ ø0.63” -0.016 ]

A

[ 0.24” -0.01 ]

B

[ 0.58” -0.016 ]

C

ø10 -0.05

ø16 -0.08

ø16 -0.4

ø18

[ ø0.71” ]

6 -0.26

14.8 -0.4

19

[ 0.75” ]

19

[ 3/4” ]

D2

D3

D4

D5

Ch

[Hex]

Exposed capillary

D1 1/2-20UNF

.307/.305”

D2

[7.80/7.75mm]

.414/.412”

D3

[10.52/10.46mm]

.125/.120”

A

[3.18/3.05mm]

.318/.312”

B

[8.08/7.92mm]

C

.81”

[20.6mm]

NOTE : dimensions refer to rigid stem length option “4” (153 mm – 6”)

WARNING : For installation use a maximum tightening torque of 56 Nm(500 in-lb)