Equipment and Calibration History
Page: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 [62] 63 64 65| Ser No. | Date | Loc From | Title | Loc To | Notes |
|---|---|---|---|---|---|
| LI-7500A 0041 | 2011-07-06 | Tonzi-Tower | Removed | Lab none | Removed from the Tonzi Tower for calibration. Replaced by sn 1594. |
| LI-7500A 0073 | 2011-07-06 | Lab none | Installed | Vaira Gas Analyzer CO2/H2O | Installed on the Vaira tower after laboratory calibration. Replaced sn 0418. |
| LI-7500A 0418 | 2011-07-06 | Vaira Gas Analyzer CO2/H2O | Removed | Lab none | Removed from the Vaira tower for calibration. Replaced by sn 0073. |
| LI-190SA Q29881 | 2011-06-18 | Lab none | Loaned | Siyan | Loaned to Siyan for her work at Teakettle Forest. |
| HMP45A U2120013 | 2011-06-18 | Lab none | Loaned | Siyan | Loaned to Siyan for her work at Teakettle Forest. |
| CR10X 31307 | 2011-06-18 | Lab none | Loaned | Siyan | Loaned to Siyan for her work at Teakettle Forest. |
| CR10X 47253 | 2011-06-13 | Lab none | Upgrade | Lab none | I upgraded the firmware on this data logger from OS Rev 22 to OS Rev 23. |
| FMA RMT-200 08-0114 | 2011-06-10 | Lab none | Installed | Twitchell Rice | Installed at Twitchell to replace sn 05-0010 which was hanging up on boot. No problems during install. |
| FMA RMT-200 05-0010 | 2011-06-10 | Twitchell Rice | Removed | Lab none | Removed from Twitchell island because it was hanging up during boot. Frank discovered it on June 6th. |
| FMA RMT-200 08-0114 | 2011-06-06 | Lab none | Calibration | Lab none | Calibrated with the god bottle 1.8978ppm at 400psi.
Last calibration Dec 12, 2010 14:03PST, 18.95C, 143.22Torr, 16.043usec, 1Hz, 2.245ppm Post cal CH4 read 1.897ppm. |
| Quantum Q29882 | 2011-06-02 | Lab none | Loaned | Loaned | Loaned to Sam Blanchard |
| CR10X 31307 | 2011-06-01 | Factory | Returned | Lab none | Returned from repair at Campbell. Campbell says, "Unit would not respond when received. Replaced PLD chip and installed OS Rev 23. Tested unit on the bench. Ran unit in the environmental chamber. Retested unit and checked calibration. Verified unit would work with SDI12 sensors."
Calibration good until May 25, 2013. |
| CR10X 20139 | 2011-05-27 | Lab none | Installed | Sherman Island | The silver data logger module of this CR10X was removed from its wiring panel and was swapped into the wiring panel of the Sherman met set to replace the original data logger that seemed to have been locked up by a bad program. |
| CR10X 36771 | 2011-05-27 | Lab none | Installed | Sherman Island | Installed at Sherman to collect the fast radiation from the diffuse PAR. Previous data logger broken in situ and was removed earlier for repair. |
| CR10X 47253 | 2011-05-27 | Sherman Island Data Logger Met | Removed | Lab none | The silver data logger module was removed from the tower. The wiring panel remained in place with a new data logger module. |
| CS511 DO-1 | 2011-05-25 | Lab none | Installed | Mayberry DO Sensor B | Installed on the Mayberry Tule Tower after being repaired in the lab. The broken cable was spliced near the sensor head. The sensor innards were also soaked in vinegar and electrolyte was replaced. |
| CS511 DO-1 | 2011-05-13 | Mayberry DO Sensor A | Removed | Lab none | The cable was broken in trying to move the sensor at Mayberry. It was returned to the lab for repair and maintenance. |
| LI-7500A 0042 | 2011-05-25 | Mayberry Gas Analyzer CO2/H2O | Removed | Lab none | Removed from the Mayberry tower for calibration. Replaced by sn 0065. |
| LI-7500A 1594 | 2011-05-25 | Twitchell Rice Gas Analyzer CO2/H2O | Removed | Lab none | Removed from the Twitchell tower for calibration. Replaced by sn 0035. |
| LI-7500A 0065 | 2011-05-25 | Lab none | Installed | Mayberry Gas Analyzer CO2/H2O | Installed on the Mayberry tower to swap out sn 0042 for calibration |
| LI-7500A 0035 | 2011-05-25 | Lab none | Installed | Twitchell Rice Gas Analyzer CO2/H2O | Installed on the Twitchell tower to swap out sn 1594 for calibration |
| CR10X 31307 | 2011-05-17 | Lab none | Repair | Factory | Sent to Campbell Scientific for evaluation and repair on RMA 13443 |
| FMA RMT-200 08-0114 | 2011-04-12 | Lab none | Repair | Lab none | The main power supply that was blown by a power surge on 2010/12/5 was replaced. The new power supply is
Mouser #: 784-HCC15-3-AG Mfr. #: HCC15-3-AG Desc.: Power One Linear & Switching Power Supplies +12- 12V, 3.4/3.4A All seems well - but needs to be calibrated |
| CR10X 31307 | 2002-07-22 | Factory | Calibration | Factory | Calibrated at Campbell. due 2003. |
| CR10X 31307 | 2011-05-13 | Sherman Island Data Logger Fast Rad | Removed | Lab none | Removed from Sherman diffuse radiation because I could not connect to it. It seemed to function at night (cool temperatures?) but did not work during the day. |
| CR10X 36771 | 2011-05-02 | Loaned | Returned | Lab none | Returned by Sara Winsemius after field use recording wind speed from a Handar 2D sonic. |
| FGGA 09-0011 | 2011-05-13 | Lab none | Maintenance | Lab none | On first power up CH4 and H2O did not line lock. I adjusted the VO setting in the linelock_0.ini file from -0.690 to -0.590.
I did a calibration with the CH4 god bottle 1.8978ppm CH4, 350psi. Last cal was: CH4 - 14 Jul 2010 H2O, CO2 - 13 Mar 2009 Precal: 14:26PST, 22.77C, 138.11Torr, 14.052usec, 1Hz, 2.058ppm After cal: 1.9021ppm |
| PRB-K Type #8 00000128B8072 | 2011-03-22 | Lab none | Installed | Sherman Island | Installed on the north side of the area inclosed by the cow fence near the soil CO2 probes. |
| PRB-K Type #8 00000128B8072 | 2011-01-27 | Factory | Returned | Lab none | Returned from ESI after being checked. No problems found. |
| PRB-K Type #8 00000128B8072 | 2010-12-07 | Lab none | Shipped | Factory | This probe was sent to ESI to check out strange readings seen in the field and the lab. |
| WM 1590 074417 | 2009-09-17 | Factory | Returned | Lab none | Returned from PP Systems for and upgrade of the firmware to fix smoothing problem with air temperature. |
| WMP 1352 000022 | 2009-05-26 | Factory | Returned | Lab none | Returned from PP Systems after being repaired by Gill. The head was bent and had to be replaced and then tested to spec. |
| WMP 1352 000022 | 2009-02-17 | Lab none | Shipped | Factory none | Sent to PP Systems for repair. |
| WMP 1352 000022 | 2011-04-26 | Mayberry Tower | Removed | Lab none | Removed from the Mayberry tower, because it seemed to quit sending data. |
| SI-121 1281 | 2011-03-01 | Lab none | Installed | Mayberry Infrared Temperature Vegetation | Installed on the Mayberry Tule Tower facing a stand of tules. |
| SI-121 1282 | 2011-03-01 | Lab none | Installed | Mayberry Infrared Temperature Water | Installed on the Mayberry Tule Tower facing open water. |
| 1189PC 000196 | 2011-04-18 | Mayberry | Removed | Lab none | Removed from the Mayberry tower where it was sitting idle after being replaced with a RS422 to RS232 converter. |
| CR10X 36771 | 2011-04-08 | Lab none | Loaned | Loaned | Loaned to undergraduate, Sara Winsemius. |
| CR10X 36771 | 2011-04-08 | Lab none | Maintenance | Lab none | The internal lithium battery was at 2.7V, probably okay (manual says okay to 2.4V) but I replaced it. Then it was acting funny so I updated its OS to v22. |
| 278 4505052 | 2011-01-28 | Lab none | Installed | Mayberry Barrometer | Installed in the data logger box on the Mayberry Tower. |
| 278 4505052 | 2010-11-14 | Factory | Calibration | Factory | Initial factory calibration. Certificate on file. |
| AM16/32B 3052 | 2011-03-01 | Lab none | Installed | Mayberry Multiplexer Met | Installed at the new Mayberry Tule Tower in about 1m of mater near a tule patch about 65m north east of the Mayberry tower. |
| AM25T 2424 | 2011-03-01 | Lab none | Installed | Mayberry Multiplexer Thermocouple | Installed at the new Mayberry Tule Tower in about 1m of mater near a tule patch about 65m north east of the Mayberry tower. |
| CR10X 35474 | 2008-07-13 | Factory | Calibration | Factory | Factory calibration at Campbell. |
| CR10X 35474 | 2011-03-01 | Lab none | Installed | Mayberry Data Logger Tule | Installed at the new Mayberry Tule Tower in about 1m of mater near a tule patch about 65m north east of the Mayberry tower. |
| FGGA 09-0010 | 2011-03-21 | Lab none | Adjusted | Lab none | I had to adjust the line lock for CH4 and H2O again. I changed it from 0.245 to 0.255. Also some strange computer lock up pausing on boot. But seems okay. |
| BB-Fab BB-TT | 2011-03-11 | Tonzi-Tower | Replaced | Tonzi-Tower | I replaced the existing batterys with new Exide deep cycle flooded lead acid batterys from OReilly Auto Parts. Four were manufactured feb 2011, two Jan 2011 and six Sep 2010. Cost was approximately 00. |
| CR10X 36771 | 2006-11-06 | Factory | Calibration | Factory | Factory calibration. Next cal due 6 Nov 2008. |
| CR10X 36771 | 2011-03-14 | Loaned | Returned | Lab none | Returned to us from Whendee Silver's lab who said that it was given to them about five years ago by Ted. |
| LI-7500A 0041 | 2011-01-24 | Lab none | Repair | Factory | Sent to licor for repair. No signal, Max AGC. |
| LI-7500A 0041 | 2011-03-07 | Factory | Repair | Lab none | Returned from repair at Licor. The lamp and the detector were bad and replaced. Licor did a full calibration resulting in new internal coefficients:
CO2 H2O A=1.32620e2 A=4.86118e3 B=6.20216e3 B=3.14261e6 C=3.33744e7 C=1.38738e8 D=-9.37277e9 E=1.14146e12 XS=0.0006 XS=-0.0010 Z=1.60000e-3 Z=1.18000e2 Pressure A0=10.697 A1=26.036 CO2 zero = 1.0020, span = 1.0025 (@ 611ppm) H2O zero = 0.8170, span = 0.9984 (@ 12C) |
| HFP01SC 00067 | 2011-03-01 | Lab none | installed | Mayberry Heat Flux Plate Water | Installed on the Mayberry tule tower measuring soil heat flux in water. |
| HFP01 000141 | 2011-03-01 | Lab none | Installed | Mayberry Heat Flux Plate Vegetation | Installed on the Mayberry tule tower measuring soil heat flux in the tules. |
| PAR-LITE 10162 | 2011-03-01 | Lab none | Installed | Mayberry PAR Sensor Incoming | Installed on the Mayberry tule tower measuring incoming PAR. |
| PAR-LITE 010163 | 2011-03-01 | Lab none | Installed | Mayberry PAR Sensor Reflected Veg | Installed on the Mayberry tule tower measuring PAR reflected from tules. |
| PAR-LITE 010161 | 2011-03-01 | Lab none | Installed | Mayberry PAR Sensor Reflected Water | Installed on the Mayberry tule tower to measure PAR relfected from open water. |
| NR-LITE 990350 | 2011-03-01 | Lab none | Installed | Mayberry Net Radiometer Water | In stalled on the Mayberry tule tower over the water. |
| CMP 11 996981 | 2001-05-20 | Lab none | Installed | Tonzi-Tower | Installed on the top of Tonzi Tower. [Gleaned from notes] |
| LI-7700 TG1-0100 | 2011-03-12 | Factory | Calibration | Factory | Zero = -8.76433 Span = 0.000099534
lasermoddepth = 14200 laserstarttemp = 22.57 blockstrattemp = 30 blockstarttemplowrange = 5 rssidropthresh = 0 pzero = 57.02 pspan = 15.25 samplegain = 0 refgain = 0 mirrorpos = 0 offset1 = 32768 delta1 = 58 offset2 = 0 delta2 = 0 dither = 30000 sampledcoffset = 241 sampleacoffset = -1392 sampleopticaloffset = 0 |
| CR10X 25799 | 2011-01-28 | Mayberry Data Logger Tule | Removed | Lab none | This CR10X was swapped out for a CR23x borrowed from the Goldstein lab. Some data was lost from final storage, but the most recent data was okay. I'm planning to use a 23x at the tower in the long term. |
| LI-7500A 0418 | 2011-02-08 | Sherman Island Gas Analyzer CO2/H2O | Removed | Lab none | This LI7500 was removed from the Sherman Island tower for calibration. sn 0073 was installed. |
| LI-7500A 0073 | 2011-02-08 | Lab none | Installed | Sherman Island Gas Analyzer CO2/H2O | This LI7500 was installed on the Sherman Island tower. sn 0418 was removed for calibration. |
| LI-7500A 0073 | 2011-02-08 | Lab none | Calibration | Lab none | Calibrated in the lab
100.82kPa, 17.57C, 58% AGC, -1.18C Td Zero Air 0.0 @ 1600psi, CO2 tank 597.4ppm @ <100psi, 2.05 C Td Last cal Oct 13, 2010 CO2 zero 0.9588 -> 0.9581 offset -2.40 ppm CO2 span 0.9974 -> 0.9979 offset +0.8 ppm H2O zero 0.7319 -> 0.7303 offset -10.0 mmol/m3 H2O span 0.9821 -> 1.0362 offset +1.16 SDM address: 7, DAC 1: 0-1000, DAC 2: 10-25 |
| LI-7700 TG1-0100 | 2010-06-22 | Lab none | Installed | Loaned none | Installed at Frank's tower in the middle of East Pond. |
| LI-7700 TG1-0100 | 2010-05-20 | Twitchell Rice 0 | Removed | Sherman Island-Levee Gas Analyzer CH4 | The Li7700 was removed from the Twitchell tower for installation on the Levee tower at Sherman. |
| LI-7700 TG1-0100 | 2010-05-05 | Lab none | Installed | Twitchell Rice Gas Analyzer CH4 | Received from Liukang Xu of licor. Installed on the Twitchell tower. Single ended analog outs are being used to record the LI7700 data on the CR1000:
Channel 0V 5V wire CH4 (mmol/m3) 0.05 0.15 wht CH4 (ppm) 1 5 brn Pressure (kPa) 90 110 grn Temperature (C) 0 50 yel RSSI (%) 0 100 gry The mirrors are set to clean at an RSSI value of 20%. USB logging is set up at 10Hz. |
| LI-7700 TG1-0100 | 2010-07-28 | Sherman Island Gas Analyzer CH4 Open-path | Removed | Twitchell Rice Gas Analyzer CH4 | I removed the LI7700 from the Sherman tower for installation at Twitchell. |
| FMA RMT-200 05-0010 | 2010-10-01 | Twitchell Rice | Removed | Lab none | The air conditioning had failed or been over come by unusually hot weather and the box got really hot (~60C). The LGR had crashed but the pump was running. Starting at stopping the pump and LGR might have back flushed fine particals into the cell. The ring time was down to 4usec. I removed the LGR for mirror cleaning. |
| FMA RMT-200 08-0114 | 2009-11-04 | Lab none | Installed | Sherman-2ndTower | Installed with the LGR trailer at Sherman Island. |
| FMA RMT-200 05-0010 | 2010-01-14 | Sherman Island | Calibration | Sherman Island | Calibrated with 1.976ppm CH4 secondary standard in the field. Pre-cal the LGR read 1.981ppm at 19.67C, 59.08Torr, 14.747usec. |
| FMA RMT-200 05-0010 | 2009-12-28 | Sherman Island | Calibration | Sherman Island | Calibration checked with 1.976ppm CH4 secondary standard in the field. LGR read 1.976ppm at 17.79C and 58.5Torr. No calibration necessary. |
| FMA RMT-200 05-0010 | 2009-06-09 | Sherman Island | Calibration | Sherman Island | Notes from 7-9-2010 say that the LGR reports its last calibration was June 9th. |
| FMA RMT-200 05-0010 | 2009-07-09 | Sherman Island | Calibration | Sherman Island | Calibrated with 1.976ppm CH4 secondary standard in the field. Pre-cal LGR read 1.994ppm. |
| FMA RMT-200 05-0010 | 2009-11-19 | Sherman Island | Calibration | Sherman Island | Calibrated with 1.976ppm CH4 secondary standard in the field. Pre-cal LGR read 2.014ppm. Last calibration was 9-17-2009 |
| FMA RMT-200 08-0114 | 2009-08-25 | Sherman Island | Calibration | Sherman Island | calibrated in the field with 1.976ppm CH4 secondary standard. Pre-cal LGR read 1.990ppm at 23.46C and 15.22usec. Last cal was 8-6-2009 |
| FMA RMT-200 08-0114 | 2009-08-06 | Sherman Island | Calibration | Sherman Island | Calibrated in the field with 1.976ppm CH4 secondary standard. Ring time was 15.5usec. |
| LI-7700 TG1-0100 | 2010-06-16 | Twitchell Rice Gas Analyzer CH4 | Installed | Lab none | Moved from Twitchell Rice to Frank's tower in the middle of East Pond. It did not power up, so we brought it back to the lab. |
| LI-7700 TG1-0100 | 2010-06-16 | Twitchell Rice Gas Analyzer CH4 | Calibration | Twitchell Rice Gas Analyzer CH4 | Clibrated in the field with grade 5.0 ultra pure N2 and 3.276ppm CH4 secondary standard.
zero before: ~0.009 ppm zero after: ~0.000 ppm span before: ~3.333 ppm span after: ~3.277 ppm |
| AM416 14049 | 2011-02-03 | Tonzi | Removed | Lab none | Removed with other equipment from near the Floor site at Tonzi. Used in recording supplimental PAR, net, shf and RH and T. |
| CR10X 20140 | 2011-02-03 | Tonzi | Removed | Lab none | Removed from Tonzi Floor. This data logger was recording up and down PAR, net and shf from the open space near the floor solar panels and net, RH and T and shf from under the trees. |
| CR10X 20140 | 1999-10-18 | Factory | Calibration | Factory | Factory calibration. |
| HFP01 000141 | 2011-02-03 | Tonzi-Floor | Removed | Lab none | Removed from the open space neat the floor solar panels. |
| HFP01SC 00067 | 2011-02-03 | Tonzi-Floor | Removed | Lab none | Removed from under the tree near the floor tower. |
| LI-7500A 0042 | 2011-02-03 | Lab none | Installed | Mayberry Gas Analyzer CO2/H2O | This sensor was installed on the tower. sn 0073 was removed for calibration. |
| LI-7500A 0042 | 2011-02-02 | Lab none | Calibration | Lab none | Last calibration Nov 16, 2010
AGC=67, SDM=7, DAC1 0-1000 H2O, DAC2 10-25 CO2 P=101.84 kPa Tair=21.06C, Tdew=~-1C Zero air no scrub 1600psi, CO2 597.4ppm 150psi, Tdew=-7.1C Precal CO2 zero=0.9622, span=0.9827 Postcal CO2 zero=0.9605, span=0.9855 Precal H2O zero=0.7829, span=0.9693 Postcal H2O zero=0.7877, span=1.1467 CO2 zero off by -6.13ppm, span off by -2.3ppm H2O zero off by +30.7mmol/m3, span off by -2.4C The weather is warm and dry making the dew point very low and difficult to calibrate. |
| LI-7500A 0073 | 2011-02-03 | Mayberry Gas Analyzer CO2/H2O | Removed | Lab none | Removed from the Mayberry tower for calibration. |
| HMP45A U2120013 | 2010-03-16 | Lab none | Installed | Tonzi-Floor | Installed under the trees near the floor tower. |
| HMP45A U2120013 | 2011-02-03 | Tonzi-Floor | Removed | Lab none | Removed from under the trees near the floor tower. |
| NR-LITE 041556 | 2011-02-03 | Tonzi-Floor | Removed | Lab none | Removed from the open space near the floor solar panels. |
| NR-LITE 990350 | 2011-02-03 | Tonzi | Removed | Lab none | Removed from under the trees near the floor tower. |
| PAR-LITE 010163 | 2011-02-03 | Tonzi | Removed | Lab none | Removed from the open space near the floor solar panels. |
| PAR-LITE 010161 | 2011-02-03 | Tonzi | Removed | Lab none | Removed from the open space near the floor solar panels. |
| LI-7500A 0042 | 2011-01-28 | Twitchell Rice Gas Analyzer CO2/H2O | Removed | Lab none | This sensor was removed from the Twitchell tower for calibration in the lab. sn 1594 was swapped in. |
| LI-7500A 1594 | 2011-01-28 | Lab none | Installed | Twitchell Rice Gas Analyzer CO2/H2O | This sensor was installed on the Twitchell tower to swap out sn 0042 for calibration. |
| LI-7700 TG1-0155 | 2011-01-31 | Lab none | Calibration | Lab none | On 1/27/11, Dennis and Jaclyn tested the LI-7700 output against the calibration gases in the lab.
1. The tank with 4.982 ppm methane read 5.021 ppm on the LI-7700. 2. The zero air tank read 0.05 ppm on the LI-7700 (although low confidence that the gas is in fact zero methane. 3. The 1.8978 god bottle read 1.898 on the LI-7700. We chose not to calibrate the instrument since the readings were so close to the actual values. |
| CS525 pH-1 | 2011-01-27 | Lab none | Calibration | Lab none | Jaclyn Hatala calibrated the pH probe on 1/27/11.
1. First I obtained the following buffers from the Barker storeroom: 1-0240 (pH4) and 1-0250 (pH7) to do a 2 point calibration. 2. Following the instructions for calibration in Appendix A of the manual, I submerged the probe in the pH 7 buffer solution and measured the mV output using the datalogger program: MBCR23x_TOWERMET_V100. 3. After recording measurements for 10 minutes, I rinsed the probe with deionized water and gently dried it. 4. Next I submerged it in the pH 4 buffer solution and recorded the mV output for 10 minutes. 5. I calculated the slope between the 2 measurements to get the multiplier in pH/mV = -0.0173 pH/mV. |
| CS547A 5688 | 2011-01-27 | Lab none | Calibration | Lab none | Jaclyn Hatala did a temperature correction calibration for the EC probe on 1/27/11.
1. First, I submerged the probe in water of 25C for 10 minutes and recorded the uncorrected EC values from the datalogger program MBCR23X_TOWERMET_V100. 2. Next, I submerged the probe in water of 20C for 10 minutes and recorded the uncorrected EC values. 3. I used the formula TC=100 * (C-C_25)/((t-25)*C_25) provided by the Campbell manual to calculate the temperature correction in %/C. The value I got was 0.786%/C. 4. I changed the MBCR23x_TOWERMET_V100 program to use the uncorrected EC to provide a corrected EC value (Cond_corr). |
| LI-7500A 1594 | 2011-01-26 | Lab none | Calibration | Lab none | Last cal 2010-10-06, SMD 7 DAC1 H2O 0-1000 DAC2 CO2 10-25
AGC = 51%, T = 24.39 C, P = 101.08 kPa, Td = 1.67 C Zero air = 0.0 1700 psi CO2 = 597.4 ppm <200psi Td = -0.4 C CO2 zero = 0.8645-> 0.8647, offset +0.85 ppm CO2 span = 1.0061 -> 1.0056, offset +0.4 ppm H2O zero = 0.8938 -> 0.8932, offset -3.0 mmol/m3 H2O span = 0.9851 -> 0.9858, offset +0.03 C |
| LI-7700 TG1-0155 | 2011-01-25 | Factory | Returned | Lab none | Returned from repair at Licor. Service note say: "The spars were knocked out of alignment. The spinning mirror bearings were knocked out of alignment. Replaced the motor and realigned everything. Tested in environmental chamber from -25C to 50C. Calibrated.
Changes to settings: Zero = 23.0176 Span = 0.00010261 sampledcoffset = 430 samplescoffset = -965 |
| LI-7700 TG1-0155 | 2010-12-22 | Lab none | Repair | Factory | The new LI-7700 was returned to Licor for repair. |