HPP809A033 - TE CONNECTIVITY

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

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•

Hermetic Housing

• Humidity calibrated within +/-2% @55%RH

• Temperature measurement through NTC

10kOhms +/-1% direct output

• Small size product

• Typical 1 to 4 Volt DC output for 0 to 100%RH

at 5Vdc

DESCRIPTION

Based on the rugged HTS2035SMD humidity / temperature sensor, HTM2500LF is a dedicated humidity and

temperature transducer designed for OEM applications where a reliable and accurate measurement is needed.

Direct interface with a micro-controller is made possible with the module’s humidity linear voltage output.

FEATURES

• Full interchangeability

• High reliability and long term stability

• Not affected by water immersion

• Ratiometric to voltage supply

• Suitable for 3 to 10 Vdc supply

voltage

Humidity Sensor Specific Features

• Instantaneous de-saturation after long periods in saturation

phase

• Fast response time

• High resistance to chemicals

• Patented solid polymer structure

Temperature Sensor Specific Features

• Stable

• High sensitivity

APPLICATIONS

•

Industrial

• Process control

• Hygrostat

• Data logger

…

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

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PERFORMANCE SPECS

MAXIMUM RATINGS

Ratings Symbol Value Unit

Storage Temperature

Tstg

-

40 to

8

5

°C

Storage Humidity

RHstg

0 to 100

% RH

Supply Voltage (Peak)

Vs

12

Vdc

Humidity Operating Range

RH

0 to 100

% RH

Temperature Operating Range

Ta

-

40 to

8

5

°C

Peak conditions: less than 10% of the operating time

ELECTRICAL CHARACTERISTICS

(Ta=23°C, Vs=5Vdc +/-5%, R

L

>1MΩ unless otherwise stated)

Humidity Characteristics Symbol Min Typ Max Unit

Humidity Measuring Range

RH

1

99

%RH

Relative Humidity Accuracy (10 to 95% RH)

RH

+/

-

3

+/

-

5

%RH

Supply Voltage

Vs

4.75

5.00

5.25

Vdc

Nominal Output @55%RH (at 5Vdc)

Vout

2.4

2

2.48

2.54

V

Current consumption

Ic

1.

0

1.

2

mA

Temperature Coefficient (10 to 50°C)

Tcc

+0.1

%RH/°C

Average Sensitivity from 33% to 75%RH

∆Vout/∆RH

+2

6

mV/%RH

Sink Current Capability (R

L

=15kΩ)

Is

300

µA

Recovery time after 150 hours of con

densation

tr

10

s

Humidity Hysteresis

+/

-

1.5

%RH

Long term stability

T

+/

-

0.5

%RH/yr

Time Constant (at 63% of signal, static) 33% to 76%RH

(1)

τ

5

s

Output Impedance

Z

70

Ω

(1) At 1m/s air flow

(Ta=25°C)

* For temperature upper than 60°C, specific high te mperature cable is required: HTM2500LFL products

Temperature Characteristics

Symbol

Min

Typ

Max

Unit

Nominal Resistance @25°C R 10 kΩ

Beta value: B25/50 β 3347 3380 3413 K

Temperature Measuring Range* Ta -40 85 °C

Nominal Resistance Tolerance @25°C R

N

1 %

Beta Value Tolerance β 1 %

Response Time τ 10 s

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

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TYPICAL PERFORMANCE CURVES

HUMIDITY SENSOR

• Typical response look-up table (Vs = 5V)

RH (%)

Vout (mV)

RH (%)

Vout (mV)

10 1235 55 2480

15 1390 60 2605

20 1540 65 2730

25 1685 70 2860

30 1825 75 2990

35 1960 80 3125

40 2090 85 3260

45 2220 90 3405

50 2350 95 3555

• Modeled linear voltage output (Vs = 5V)

• Linear Equations

Vout = 26.65 * RH + 1006

RH = 0.0375 * Vout – 37.7

with Vout in mV and RH in %

• Polynomial Equations

Vout = 1.05E

-3

*

RH

3

- 1.76E

-1

*

RH

2

+ 35.2 * RH + 898.6

RH = -1.92E

-9

*

Vout

3

+ 1.44E

-5

*

Vout

2

+ 3.4E

-3

*

Vout – 12.4

with Vout in mV and RH in %

• Measurement Conditions

HTM2500LF is specified for accurate measurements within 10 to 95% RH.

Excursion out of this range (<10% or >95% RH, including condensation) does not affect the reliability of

HTM2500LF characteristics.

1000

1500

2000

2500

3000

3500

4000

0 10 20 30 40 50 60 70 80 90 100

Relative Humidity (%RH)

Output Voltage (mV)

0

10

20

30

40

50

60

70

80

90

100

1000 1500 2000 2500 3000 3500 4000

Output Voltage (mV)

Relative Humidity (%RH)

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

4/9

• Error Budget at 23°C

HTM2500LF Error Limits:

Temperature coefficient compensation:

HTM2500LF Linearity Error:

Non-linearity and temperature compensation:

with Vout in mV, RH in % and Ta in °C

( )

ET

a

out

V

E

out

V

E

Vout

E

RH

3

2

5

3

9

4.2231

4.12421.3437.19206.1

%

−

−−−

×−+

−++−

=

(

)

(

)

E

T

RH

areadCor

3

4.2231%%

−

×−−×=

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

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HTM2500LF TEMPERATURE SENSOR: DIRECT NTC OUTPUT

• Typical temperature output

Depending on the needed temperature measurement range and associated accuracy, we suggest two methods

to access to the NTC resistance values.

R

T

NTC resistance in Ω at temperature T in K

R

N

NTC resistance in Ω at rated temperature T in K

T, T

N

Temperature in K

β Beta value, material specific constant of NTC

e Base of natural logarithm (e=2.71828)

 The exponential relation only roughly describes the actual characteristic of an NTC thermistor can, however,

the material parameter β in reality also depend on temperature. So this approach is suitable for describing a

restricted range around the rated temperature or resistance with sufficient accuracy.

 For practical applications, a more precise description of the real R/T curve may be required. Either more

complicated approaches (e.g. the Steinhart-Hart equation) are used or the resistance/temperature relation as

given in tabulation form. The below table has been experimentally determined with utmost accuracy for

temperature increments of 1 degree.

Actual values may also be influenced by inherent self-heating properties of NTCs. Please refer to MEAS-France

Application Note HPC106 “Low power NTC measurement”.

• Temperature look-up table

Temp (°C)

R (Ω)

Temp (°C)

R (Ω)

-40

195652

25

10000

-35

148171

30

8315

-30

113347

35

6948

-25

87559

40

5834

-20

68237

45

4917

-15

53650

50

4161

-10

42506

55

3535

-5

33892

60

3014

0

27219

65

2586

5

22021

70

2228

10

17926

75

1925

15

14674

80

1669

20

12081

85

1452











−

×=

N

TT

NT

eRR

11

β

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

6/9

• Steinhart-Hart coefficients

According to the equation below, the Steinhart-Hart coefficients for the operating temperature range for

HTM2500LF thermistor are:

)ln(*)ln(*)ln(*)ln(*

1RRRCRba

T

++=

R

NTC resistance in Ω at temperature T in K

T Temperature in K

a Constant value (a = 8.54942E-04)

b Constant value (b = 2.57305E-04)

c Constant value (c = 1.65368E-07)

• Temperature Interface Circuit

Concerning the temperature sensor of the HTM2500LF, the following measuring method described below is

based on a voltage bridge divider circuit. It uses only one resistor component (Rbatch) at 1% to design

HTM2500LF temperature sensor interfacing circuit.

Rbatch is chosen to be equal to NTC @25°C to get: Vout = Vcc/2 @25°C.

The proposal method connects Rbatch to Vcc (5Vdc) and NTC to Ground. It leads to a negative slope

characteristic (Pull-Up Configuration).

Temp (°C) R (Ω)

Pull

-

up Configuration

Vout (mV)

-40

195652

4757

-30

113347

4595

-20

68237

4361

-10

42506

4048

0

27219

3657

10

17926

3210

20

12081

2736

25

10000

2500

30

8315

2270

40

5834

1842

50

4161

1469

60

3014

1158

70

2228

911

80

1669

715

W4

NTC Resistance output

HTM2500LF NTC

10kΩ @25°C

Vout (mV)

W2

VCC

Rbatch

10kΩ

W1

Ground

)()( )(*)(

)(

2500

Ω+Ω

Ω

=

LFHTMbatch

LFHTM

OUT

NTCR NTCmVVcc

mVV

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

7/9

SUGGESTED APPLICATION

QUALIFICATION PROCESS

RESISTANCE TO PHYSICAL AND CHEMICAL STRESSES

• HTM2500LF has passed through qualification processes of MEAS-France including vibration, shock,

storage, high temperature and humidity, ESD.

• Additional tests under harsh chemical conditions demonstrate good operation in presence of salt

atmosphere, SO2 (0.5%, H2S (0.5%), 03, NOx, NO, CO, CO2, Softener, Soap, Toluene, acids (H2SO4,

HNO3, HCI), HMDS, Insecticide, Cigarette smoke, this is not an exhaustive list.

• HTM2500LF is not light sensitive.

SPECIFIC PRECAUTIONS

• HTM2500LF is not protected against reversed polarity - Check carefully when connecting the device.

• If you wish to use HTM2500LF in a chemical atmosphere not listed above, consult us.

Steps of 1% RH are achievable by

using 8-bit A/D.

If more resolution is required, a 10-

bit A/D needs to be used and a third

display will be added, giving steps of

0.2% RH.

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

8/9

PACKAGE OUTLINE

HTM2500LF weight: 17.5g

HTM2500LFL weight: 50g

HTM2500LF wire characteristics: AWG 24 for W1, W2, W3 and W4 / AWG 16 for W5

HTM2500LFL wire characteristics: AWG 24 for W1, W2, W3 and W4 / AWG 16 for W5

Dim Min (mm) Max (mm)

A 53 55

B 74.3 76.3

C 11.2 11.6

D*

(HTM2500LF) 200 250

D*

(HTM2500LFL) 1450 1550

*Specific length available on request

For operating temperature upper than 60°C, specific high temperature

cable is required

(1500mm long)

Wire Cable Color

HTM2500LF

Cable Color

HTM2500LFL Function

W1 Brown Black Ground

W2 White Orange Supply Voltage

W3 Yellow Yellow Humidity Voltage Output

W4 Green Purple Temperature Output

(NTC Direct)

W5 Black (thick) Black (thick) Shield

HTM2500LF – Temperature and Relative Humidity Module

HTM2500LF HPC169 Rev C www.meas-spec.com October 2012

9/9

ORDERING INFORMATION

HPP809A031 : HTM2500LF

HUMIDITY VOLTAGE OUTPUT + NTC (TEMPERATURE DIRECT OUTPUT)

HPP809A033 : HTM2500LFL

HUMIDITY VOLTAGE OUTPUT + NTC (TEMPERATURE DIRECT OUTPUT) WITH LONG CABLE

(MULTIPLE PACKAGE QUANTITY OF 10 PIECES)

Customer Service contact details

Measurement Specialties, Inc - MEAS France

Impasse Jeanne Benozzi

CS 83 163

31027 Toulouse Cedex 3

FRANCE

Tél: +33 (0)5 820 822 02

Fax: +33(0)5 820 821 51

Sales: humidity.sales@meas-spec.com

Revision Comments Who Date

0 Document creation D. LE GALL July 09

A Temperature operating range updated, HTM25X0LFL

references added D. LE GALL December 09

B New MEAS template, Temperature operating range

updated, RH polynomial equation modified, package

outline

paragraph updated

D. LE GALL January 12

C New combined RH/Temp sensor implemented,

HTM2530LF product reference deleted D. LE GALL October 12

The information in this sheet has been carefully reviewed and is believed to be accurate; however, no responsibility is assumed for

inaccuracies. Furthermore, this information does not convey to the purchaser of such devices any license under the patent rights to the

manufacturer. Measurement Specialties, Inc. reserves the right to make changes without further notice to any product herein. Measurement

Specialties, Inc. makes no warranty, representation or guarantee regarding the suitability of its product for any particular purpose, nor does

Measurement Specialties, Inc. assume any liability arising out of the application or use of any product or circuit and specifically disclaims

any and all liability, including without limitation consequential or incidental damages. Typical parameters can and do vary in different

applications. All operating parameters must be validated for each customer application by customer’s technical experts. Measurement

Specialties, Inc. does not convey any license under its patent rights nor the rights of others.