BAPI LM334 Room Sensors Catalog Page

LM334 Room Sensors

Sensor Termination and T roubleshooting

9613_ins_LM334_Room

Termination

BAPI recommends using twisted pair of at least 22 AWG and crimp type connectors for all wire connections. Also, it is
recommended that wiring NOT be run in the same conduit as line voltage wiring or with wiring used to supply highly
inductive loads such as motors, generators, and coils.

11/22/06rev.

LM334 (2 Wire) sensors

1. Install a 10K 0.1% resistor between the sensor
Output (terminal 2) and Ground (GND).

2. Make sure that the resistor is connected
between the analog input (A.I.) point and

Ground.

3. Connect the sensor Output to the A.I. point.

4. Connect the 5 to 30 VDC wire last.

SENS

R1

R2

1
2
3

+5 to +30 VDC [To Power of Controller or Supply]

Sensor output (1mV/°K) [To Analog Input of Controller]

10K 0.1%

GND(Common) [To GND(Common) of Controller]

LM334-10K (3 Wire) sensors

1. All LM334-10K (3 wire) sensors have a 10K

0.1% resistor built in.

2. Connect the Ground (terminal 3) wire first.

3. Connect the Sensor Output wire second.

4. Connect the 5 to 30 VDC wire last.

SENS

R1

R2

1
2
3

+5 to +30 VDC [To Power of Controller or Supply]

Sensor output (1mV/°K) [To Analog Input of Controller]

GND(Common) [To GND(Common) of Controller]

Offsetting

All LM334 sensors will have the following information provided on a label:

Therm Reading_______

The actual temperature reading
according to a thermometer that is
certified traceable to recognized
standards by the National Institute of
Standards and Technology (NIST).

To correct the Sensor Reading, simply add the offset value to the sensor reading so that it equals the thermometer
reading.

e.g. Therm Reading 74.6 Sensor Reading 73.0 Offset +1.6

Correction: Add (+1.6) °F to the sensor for an accurate reading: 73 + 1.6 = 74.6°F

e.g. Therm Reading 75.4 Sensor Reading 77.2 Offset -1.8

Correction: Add (-1.6) °F to the sensor for an accurate reading: 77.2 + (-1.8) = 75.4°F

Sensor Reading ______

The temperature reading according
to the LM334 sensor, using the
output in either mA or mV and
converting the output to a Fahrenheit
temperature.

Offset_______

The difference between the
Thermometer Reading and the
Sensor Reading

1

9613_ins_LM334_Room

Troubleshooting

LM334 Room Sensors

Sensor Termination and T roubleshooting

11/22/06rev.

Problems:

Temperature sensor in front end software is reading
high

Temperature sensor in front end software is reading
low

Temp. LM334

°F °C (µA) (V)
50 10 283.2 2.83
60 15.56 288.7 2.89
62 16.67 289.8 2.90
64 17.78 290.94 2.91

Possible Solutions:

- Confirm the input is set up correctly in
the front end software

- Check wiring for proper termination

- Verify the “Sensor” output is correct
from Pin 2 to Pin 3
Refer to table below for proper reading

- Determine if the semiconductor appears physically
shorted

- Check wiring for proper termination

- Verify the “Sensor” output is correct
from Pin 2 to Pin 3
Refer to table below for proper reading

66 18.89 292.1 2.92
68 20 293.2 2.93
70 21.11 294.3 2.94
72 22.22 295.4 2.95
74 23.33 296.5 2.97
76 24.44 297.6 2.98
77 25 298.2 2.98
78 25.56 298.7 2.99
80 26.67 299.8 3.00
82 27.78 300.9 3.01
84 28.89 302.1 3.02
86 30 303.2 3.03
88 31.11 304.3 3.04
90 32.22 305.4 3.05
100 37.78 310.9 3.10

2