ES-3111 Rev.7

BT

Space-saving Two-wire Signal Conditioners B-UNIT

THERMOCOUPLE TRANSMITTER

(non-isolated)
Functions & Features
• Accepting direct input from a thermocouple and providing a standard 4 – 20 mA DC signal
• Burnout protection
• High-accuracy cold junction compensation
• High-density mounting

MODEL: BT–[1][2]

ORDERING INFORMATION

• Code number: BT-[1][2]
Specify a code from below for each of [1] and [2].
  (e.g. BT-2/BL/Q)
• Temperature range (e.g. 0 – 800°C)
• Specify the specification for option code /Q
  (e.g. /C01/S01)

[1] INPUT THERMOCOUPLE

2: K (CA) (Usable range -270 to +1370°C, -454 to +2498°F)
3: E (CRC) (Usable range -270 to +1000°C, -454 to +1832°F)
4: J (IC) (Usable range -210 to +1200°C, -346 to +2192°F)
5: T (CC) (Usable range -270 to +400°C, -454 to +752°F)
7: R (Usable range -50 to +1760°C, -58 to +3200°F)
8: S (Usable range -50 to +1760°C, -58 to +3200°F)

[2] OPTIONS (multiple selections)

Burnout
blank: Upscale burnout
/BL: Downscale burnout
/BN: No burnout
Other Options
blank: none
/Q: Option other than the above (specify the specification)

SPECIFICATIONS OF OPTION: Q (multiple selections)

COATING (For the detail, refer to our web site.)
/C01: Silicone coating
/C02: Polyurethane coating
/C03: Rubber coating
TERMINAL SCREW MATERIAL
/S01: Stainless steel

GENERAL SPECIFICATIONS

Construction: Plug-in
Connection: M3.5 screw terminals (torque 0.8 N·m)
Screw terminal: Nickel-plated steel (standard) or stainless steel
Housing material: Flame-resistant resin (black)
Zero adjustment: -5 to +5 % (front)
Span adjustment: 95 to 105 % (front)
Linearization: Not provided
Cold junction compensation: CJC sensor attached to the
input terminals

INPUT SPECIFICATIONS

Minimum span: 3 mV
Offset: Max. 1.5 times span
Input resistance: 50 kΩ minimum
Burnout sensing: 0.25 μA
Minimum span (in °C)
K (CA)
: 75°C
E (CRC): 50°C
J (IC): 60°C
T (CC): 75°C
R: 360°C
S: 380°C

Minimum span (in °F)
K (CA)
: 140°F
E (CRC): 90°F
J (IC): 110°F
T (CC): 140°F
R: 650°F
S: 690°F

OUTPUT SPECIFICATIONS

Output: 4 – 20 mA DC
Load resistance vs. supply voltage:
Load Resistance (Ω) = (Supply Voltage (V) – 12 (V)) 
÷ 0.02 (A)     (including leadwire resistance)

INSTALLATION

Supply voltage: 12 – 60 V DC
Operating temperature: -5 to +60°C (23 to 140°F)
Operating humidity: 30 to 90 %RH (non-condensing)
Mounting: Surface or DIN rail; Standard Rack Mounting Frame BX-16H available
Weight: 150 g (0.33 lb)

PERFORMANCE in percentage of span

Accuracy: ±0.1 % (at over 400°C or 750°F for R and S)
Cold junction compensation error (at 20°C or 68°F)
  K, E, J & T: ±0.5°C or ±0.9°F
  S & R: ±1°C or ±1.8°F
Temp. coefficient: ±0.05 %/°C (±0.03 %/°F)
(at over 400°C or 750°F for R and S)
Response time: ≤ 0.5 sec. (0 – 90 %)
Burnout response: ≤ 10 sec.

EXTERNAL DIMENSIONS unit: mm [inch]

TERMINAL ASSIGNMENTS unit: mm [inch]

SCHEMATIC CIRCUITRY & CONNECTION DIAGRAM