The BAPI BA/1K-I-2"-WPO is an immersion temperature sensor with a 1000 Ohm Platinum RTD (385 Curve) sensing element, potted in a 2 inch (51 mm) long, 0.25 inch OD 304 stainless steel probe with thermally-conductive compound. The probe threads into a thermowell via a 1/2 inch NPSM nylon fitting; on hand-tightening the probe slides up to 1.6 inch inside the enclosure body so the tip seats firmly against the thermowell bottom, giving solid thermal contact regardless of thermowell depth tolerance.
The sensor outputs resistance directly to the BAS analog input (no powered signal conditioning). The BAS converts resistance to temperature using a sensor-specific R/T table programmed in the controller. The unit is housed in the Weatherproof Cast Aluminum (Outside Mount) enclosure (NEMA 3R / IP14, Die-Cast Aluminum, BAPI-Bell with hinged cover) and wired for Flying Leads. The Outside-Mount (O) configuration orients the mounting flange on the OUTSIDE of the enclosure body, which suits applications where the enclosure must be flush against a panel or wall and the probe exits from the rear. Made in USA by BAPI of Gays Mills, Wisconsin.
Water-pipe, hydronic-loop, cooling-tower-sump, and tank temperature measurement on BAS systems that accept resistance-input directly (1000 Ohm Platinum RTD (385 Curve)). The 2 inch (51 mm) probe fits a matching BAPI thermowell of the same length; for a typical 8 inch insulated pipe, a 4 inch probe in a 4 inch thermowell reaches the centerline (best-case thermal contact with the flowing media).
Key Features
1000 Ohm Platinum RTD (385 Curve) potted inside a 0.25 inch OD 304 stainless steel probe with thermally-conductive compound. Etched Teflon leadwire is plenum-rated. The double encapsulation keeps the sensor watertight under 100% RH non-condensing service.
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.
Mounting flange located on the OUTSIDE of the enclosure body - the probe exits from the rear and the enclosure mounts flush to a panel or wall. Useful in tight wiring closets and slim-profile installations.
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/1K-I-2"-WPO |
| Series | BAPI Immersion w/ Nylon Fitting (B40/B41) |
| Sensor Type | Passive Resistance Sensor (unpowered) |
| Temperature Element | 1000 Ohm Platinum RTD (385 Curve) |
| Nominal Resistance | 1000 Ohm at 0 degC |
| Sensitivity | 3.85 Ohm/degC (385 curve, DIN43760) |
| Output Type | Resistance (to controller analog input, no polarity) |
| Probe Length | 2 inch (51 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 (Outside Mount) |
| 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) |
| Mount Configuration | Outside-Mount (mounting flange on exterior of enclosure) |
| Agency Compliance | RoHS, CE (where applicable) |
| Country of Origin | Made in USA (Gays Mills, WI) |
Documentation
Frequently Asked Questions
BAPI strongly recommends installing this sensor inside a matching thermowell rather than direct-immersion. A thermowell lets the sensor be removed and serviced without draining or depressurizing the pipe / tank, and protects the probe from corrosion or mechanical damage. Match the thermowell length to the probe length (2 inch (51 mm)).
This sensor is a passive 1000 Ohm Platinum RTD (385 Curve). The BAS controller needs the matching R/T (resistance / temperature) curve programmed in its analog-input setup - typically selectable by manufacturer-specific table name. The full R/T table is at bapihvac.com under Resources -> Sensor Specs.
This SKU uses the Weatherproof Cast Aluminum (Outside Mount) (NEMA 3R / IP14, Die-Cast Aluminum, BAPI-Bell with hinged cover). Heavy-duty cast aluminum weatherproof bell enclosure for outdoor and harsh environments.
The mounting flange is relocated to the OUTSIDE of the enclosure body (instead of the standard inside-mount configuration). The probe exits from the rear of the enclosure and the enclosure mounts flush against a panel or wall. Useful in tight wiring closets, slim panel installations, or applications where the enclosure must be flush with the mounting surface.
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 Sensor
- Sensor Type:
- Passive Resistance Sensor
- Temperature Element:
- 1000 Ohm Platinum RTD (385 Curve)
- Output Signal:
- Resistance (to BAS analog input)
- Probe Length:
- 2 inch (51 mm)
- Probe Fitting:
- Nylon (1/2 inch NPSM Plastic)
- Calibrated Range:
- -40 to 221 degF (probe operating range, passive)
- Enclosure:
- Weatherproof Cast Aluminum
- Mount Position:
- Outside Mount
- Enclosure Rating:
- NEMA 3R / IP14
- Wiring Configuration:
- Flying Leads
- Country of Origin:
- Made in USA