The BAPI BA/T1K[2][0 TO 400F]-I-8"-WP is an immersion temperature transmitter pairing a 1000 Ohm Platinum RTD (385 curve) sensing element with an on-board signal-conditioning circuit, delivering a 4-20 mA output (2-wire loop-powered) calibrated for 0 TO 400F. This SKU is built as the extended-high-temperature variant ([2]), enabling calibrated ranges above the standard 212 degF top end. Verify probe construction details with BAPI for ranges above 250 degF. The transmitter scales the temperature span to the full output swing - the low end of the range corresponds to output low (0V / 1V / 2V / 4 mA depending on output mode), the high end to output high. 2-wire loop-powered - 12-30 VDC from the controller drives the transmitter; no separate supply at the sensor.
The probe is a 8 inch (203 mm) long, 0.25 inch OD 304 stainless steel assembly with a 1/2 inch NPSM nylon fitting for thermowell mounting; on hand-tightening the probe self-seats against the thermowell bottom. The transmitter is housed in the Weatherproof Cast Aluminum enclosure (NEMA 3R / IP14, Die-Cast Aluminum, BAPI-Bell with hinged cover) and wired for Flying Leads. Made in USA by BAPI of Gays Mills, Wisconsin.
Water-pipe, hydronic-loop, cooling-tower-sump, and tank temperature measurement on BAS controllers that need a 4-20 mA analog signal rather than a raw RTD resistance. Calibrated 0 TO 400F span suits applications where the working range falls within those endpoints (narrower ranges deliver higher resolution per degree). The probe fits a matching BAPI thermowell of the same length.
Key Features
Combines a Platinum 1000 Ohm RTD (385 curve, DIN43760) sensing element with a factory-calibrated transmitter on the same board. Eliminates the BAS R/T table lookup and external signal conditioner.
2-wire 4 to 20 mA loop-powered output. No 24 VAC/VDC supply needed at the sensor - the controller's loop power drives the transmitter. Ideal for long cable runs.
Probe and electronics rated for calibrated ranges above the standard 212 degF top end - suitable for high-temp domestic hot water, steam condensate, and process applications. Verify the maximum probe operating temperature with BAPI.
Transmitter span is set at the factory to the indicated range. Lower end of temperature span = output low (0V / 1V / 2V / 4 mA); higher end = output high.
The plastic NPSM fitting allows the probe to slide up to 1.6 inch inside the enclosure as the unit is hand-threaded onto the thermowell - probe tip self-seats against the thermowell bottom on tightening. Hand-tight only; no thread sealant required on this side.
Die-Cast Aluminum, BAPI-Bell with hinged cover. Heavy-duty cast aluminum weatherproof bell enclosure for outdoor and harsh environments.
Designed and manufactured by Building Automation Products, Inc. at 750 North Royal Avenue, Gays Mills, Wisconsin. RoHS / CE compliant.
Technical Specifications
| Specification | Value |
|---|---|
| Manufacturer | Building Automation Products, Inc. (BAPI) |
| Manufacturer Part Number | BA/T1K[2][0 TO 400F]-I-8"-WP |
| Series | BAPI Immersion w/ Nylon Fitting (B40/B41) |
| Sensor Type | Active Transmitter (powered) |
| Sensing Element | 1000 Ohm Platinum RTD, 385 Curve (DIN43760) |
| Output Signal (Factory Set) | 4-20 mA |
| Output Topology | 2-wire loop-powered |
| Output Selectability | Fixed 4-20 mA loop-powered |
| Calibrated Temperature Range | 0 TO 400F |
| Power Supply | 12-30 VDC loop-powered |
| Transmitter Modifiers | [2] - Extended-High-Temperature Variant (suitable for ranges above standard 212 degF) |
| Probe Length | 8 inch (203 mm) |
| Probe Material | 304 Stainless Steel, 0.25 inch outer diameter |
| Probe Construction | Double-encapsulated sensing element with thermally-conductive potting |
| Process Fitting | 1/2 inch NPSM Plastic (Nylon) |
| Lead Wire | 22 AWG Stranded, Etched Teflon, Plenum Rated |
| Wiring Option | Flying Leads |
| Enclosure Model | Weatherproof Cast Aluminum |
| Enclosure Rating | NEMA 3R / IP14 |
| Enclosure Material | Die-Cast Aluminum, BAPI-Bell with hinged cover |
| Enclosure Dimensions (H x W x D) | See BAPI enclosure dimension drawings (B69) |
| Enclosure Ambient Temperature | -40 to 212 degF (-40 to 100 degC) |
| Ambient Humidity | 0 to 100% RH, non-condensing |
| Mounting Method | Thermowell insertion (1/2 inch NPSM Plastic (Nylon), hand-tightened) |
| Agency Compliance | RoHS, CE (where applicable) |
| Country of Origin | Made in USA (Gays Mills, WI) |
Documentation
Mounting and probe-insertion instructions in 20907 apply to both passive and active variants since the probe / fitting / enclosure construction is identical. Active-transmitter wiring topology and output-mode jumper positions are shown on the wiring diagram inside the enclosure cover; the SS Double-Thread active install sheets (20919 / 37726) contain comparable transmitter-electronics detail.
Frequently Asked Questions
The active transmitter outputs a calibrated 4-20 mA analog signal directly proportional to temperature - the BAS reads the analog value and interprets it linearly across the calibrated span. A passive sensor outputs raw resistance which the BAS must convert using a sensor-specific R/T curve. Use the transmitter when (1) your controller doesn't have a built-in R/T table, (2) you want a longer cable run without lead-resistance error, or (3) the integrator wants to standardize on 4-20 mA / 0-10V analog signals.
This SKU is factory-calibrated for 0 TO 400F. The low end of that range corresponds to the output's low value (4 mA / 0V / 1V / 2V depending on output type); the high end corresponds to the output's high value (20 mA / 5V / 10V). Pick the narrowest span that comfortably brackets your expected working range - narrower spans give higher resolution per degree on the controller input.
2-wire loop-powered: 12-30 VDC supply, two wires carry both power and the current-modulated signal. Wire 24 VDC+ from the controller / loop power supply to the transmitter's + terminal; transmitter's - terminal returns to the controller's 4-20 mA AI. Recommended cable: 22 AWG twisted shielded pair. Ground the shield at the BAS end only.
This SKU uses the Weatherproof Cast Aluminum (NEMA 3R / IP14, Die-Cast Aluminum, BAPI-Bell with hinged cover). Heavy-duty cast aluminum weatherproof bell enclosure for outdoor and harsh environments.
Yes. BAPI Immersion sensors and transmitters are designed and manufactured by Building Automation Products, Inc. at 750 North Royal Avenue, Gays Mills, Wisconsin (USA).
- Brand:
- BAPI
- Series:
- Immersion Nylon Fitting Transmitter
- Sensor Type:
- Active Transmitter
- Temperature Element:
- 1K Platinum RTD (385 Curve, internal)
- Output Signal:
- 4-20 mA
- Probe Length:
- 8 inch (203 mm)
- Probe Fitting:
- Nylon (1/2 inch NPSM Plastic)
- Calibrated Range:
- 0 TO 400F
- Enclosure:
- Weatherproof Cast Aluminum
- Mount Position:
- Standard
- Enclosure Rating:
- NEMA 3R / IP14
- Wiring Configuration:
- Flying Leads
- Country of Origin:
- Made in USA