DS9108 Concrete Temperature Monitor www.maxim-ic.com GENERAL DESCRIPTION FEATURES This product is a sealed plastic stick containing three DS1921G iButtons®. The iButtons are connected in parallel through metal plates that are spot-welded to the IO and GND contact, respectively. Two stranded wires protruding from the top end of the stick allow for a 1-Wire® reader/write to make contact to the iButtons for setup and data retrieval. Electrically, the product is specified by the DS1921G data sheet, with the proper scaling (e.g., current ×3, capacitance ×3). The mechanical and thermal characteristics of the module are specified in this document. APPLICATIONS ORDERING INFORMATION Concrete Maturity Monitoring Three DS1921G networked to monitor temperate at the top, bottom and center of the stick Connects to 1-Wire reader/writer through colorcoded 18 AWG (1 mm Ø) stranded wires with ½ inch (1.3 cm) stripped ends Electrically compatible to the DS1921G Thermochron iButton (3 in parallel) Sealed against liquid intrusion Module position information stored in DS1921G memory PART DS9108-8# DS9108-10# DS9108-12# DS9108-15# TEMP RANGE -20°C to 65°C -20°C to 65°C -20°C to 65°C -20°C to 65°C PIN-PACKAGE 8” (20.3 cm) depth* 10” (25.4 cm) depth 12” (30.5 cm) depth 15” (38.1 cm) depth Shipped in bulk with the wires bundled with a tie * Indicates depth of concrete to monitor, actual stick length is 0.25” (0.6 cm) less then depth TYPICAL OPERATING CIRCUIT BLOCK DIAGRAM Metal plates welded to iButtons Stranded wire Ends twisted VCC RPUP* U1 U2 U3 DS1921G #1 TOP DS1921G #2 MIDDLE IO Portable 1-Wire reader Red wire Temperature Monitor IO DS1921G #3 BOTTOM GND Black wire Red Transition wire to metal plate GND Black * See Application Note 3829 for Rpup resistor size selection. iButton and 1-Wire are registered trademarks of Dallas Semiconductor. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata. 1 of 3 REV: 102106 DS9108 Concrete Temperature Module ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground Operating Temperature Range Storage Temperature Range See DS1921G Datasheet -4°F to 149°F (-20°C to +65°C) See DS1921G Datasheet Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to the absolute maximum rating conditions for extended periods may affect device. SPECIFICATIONS (See DS1921G datasheet, TA = -4°F to 149°F (-20°C to +65°C) (Note 1)) PARAMETER CONDITIONS MIN Weight Physical Dimensions TYP MAX UNITS 2.5 ounces 72 grams See technical drawing Wire Length Tensile Strength of Wires Thermal Response Time 12.9 13.1 inches 32.8 33.3 cm 10 lbf 44.5 Newton (Note 2) 500 s Note 1: Assembled module production tested at 77°F (25°C). Note 2: Response time in water is the time required for the recorded value to read 63% of the temperature’s real variation. Material: PVC with PVC cement and E-60NC black Hysol epoxy for wire sealant PIN DESCRIPTION PIN NAME Red Wire Black Wire IO GND FUNCTION 1-Wire bus interface. Open drain, requires external pull-up resistor. Ground Reference iButton LOCATION WITHIN MODULE Each DS1921G in the DS9108 module contains a memory tag marker to indicate its position in the assembly. The position mark is a CRC16 validated packet starting on page 15 in the user memory. The memory image for ‘TOP’, ‘MIDDLE’, and ‘BOTTOM’: Table 1. Memory Tag Description TAG TYPE TOP MIDDLE BOTTOM ADDRESS 1E0h–1E3h CONTENTS (HEX) 01 54 FA 60 01 4D 3B AA 01 42 7B AE 2 of 3 DESCRIPTION ‘T’ in a CRC validated packet ‘M’ in a CRC validated packet ‘B’ in a CRC validated packet DS9108 Concrete Temperature Module TYPICAL OPERATING CHARACTERISTICS The module is inserted into wet concrete with the top approximately 0.25 inches (0.6 cm) below the surface. The wires are draped on the surface for later data retrieval. Concrete Surface 0.25 PACKAGE INFORMATION 0.20 (0.5) L 0.63 (1.6) 1.10 (2.8) Bottom iButton Middle iButton Top iButton M T B Concrete Depth 8 (20.3) 10 (25.4) 12 (30.5) 15 (38.1) Inches (centimeters) L 7.75 (19.7) 9.75 (24.8) 11.75 (29.8) 14.75 (37.5) B .60 (1.5) .60 (1.5) .60 (1.5) .60 (1.5) M 3.88 (9.9) 4.88 (12.4) 5.88 (14.9) 7.38 (18.7) 3 of 3 T .60 (1.5) .60 (1.5) .60 (1.5) .60 (1.5)